Session expired randomly in laravel 5.1

session is being expired randomly after some pages requests. it is not fixed some time session expired between 10 to 15 minutes , some times session expired after 2 to 3 pages request only . And some times not every times when i posting data from a page it say's TokenMismatchException in VerifyCsrfToken.php but i've added in the form .

I'm using database driver for session. i would like to tell that before this i was using file driver for session but there was same condition.

here is my config/session.php file

``

return [

/*
|--------------------------------------------------------------------------
| Default Session Driver
|--------------------------------------------------------------------------
|
| This option controls the default session "driver" that will be used on
| requests. By default, we will use the lightweight native driver but
| you may specify any of the other wonderful drivers provided here.
|
| Supported: "file", "cookie", "database", "apc",
|            "memcached", "redis", "array"
|
*/

'driver' => env('SESSION_DRIVER', 'database'),

/*
|--------------------------------------------------------------------------
| Session Lifetime
|--------------------------------------------------------------------------
|
| Here you may specify the number of minutes that you wish the session
| to be allowed to remain idle before it expires. If you want them
| to immediately expire on the browser closing, set that option.
|
*/

'lifetime' => 120,

'expire_on_close' => false,

/*
|--------------------------------------------------------------------------
| Session Encryption
|--------------------------------------------------------------------------
|
| This option allows you to easily specify that all of your session data
| should be encrypted before it is stored. All encryption will be run
| automatically by Laravel and you can use the Session like normal.
|
*/

'encrypt' => false,

/*
|--------------------------------------------------------------------------
| Session File Location
|--------------------------------------------------------------------------
|
| When using the native session driver, we need a location where session
| files may be stored. A default has been set for you but a different
| location may be specified. This is only needed for file sessions.
|
*/

'files' => storage_path('framework/sessions'),

/*
|--------------------------------------------------------------------------
| Session Database Connection
|--------------------------------------------------------------------------
|
| When using the "database" or "redis" session drivers, you may specify a
| connection that should be used to manage these sessions. This should
| correspond to a connection in your database configuration options.
|
*/

'connection' => null,

/*
|--------------------------------------------------------------------------
| Session Database Table
|--------------------------------------------------------------------------
|
| When using the "database" session driver, you may specify the table we
| should use to manage the sessions. Of course, a sensible default is
| provided for you; however, you are free to change this as needed.
|
*/

'table' => 'sessions',

/*
|--------------------------------------------------------------------------
| Session Sweeping Lottery
|--------------------------------------------------------------------------
|
| Some session drivers must manually sweep their storage location to get
| rid of old sessions from storage. Here are the chances that it will
| happen on a given request. By default, the odds are 2 out of 100.
|
*/

'lottery' => [2, 100],

/*
|--------------------------------------------------------------------------
| Session Cookie Name
|--------------------------------------------------------------------------
|
| Here you may change the name of the cookie used to identify a session
| instance by ID. The name specified here will get used every time a
| new session cookie is created by the framework for every driver.
|
*/

'cookie' => 'laravel_session',

/*
|--------------------------------------------------------------------------
| Session Cookie Path
|--------------------------------------------------------------------------
|
| The session cookie path determines the path for which the cookie will
| be regarded as available. Typically, this will be the root path of
| your application but you are free to change this when necessary.
|
*/

'path' => '/',

/*
|--------------------------------------------------------------------------
| Session Cookie Domain
|--------------------------------------------------------------------------
|
| Here you may change the domain of the cookie used to identify a session
| in your application. This will determine which domains the cookie is
| available to in your application. A sensible default has been set.
|
*/

'domain' => null,

/*
|--------------------------------------------------------------------------
| HTTPS Only Cookies
|--------------------------------------------------------------------------
|
| By setting this option to true, session cookies will only be sent back
| to the server if the browser has a HTTPS connection. This will keep
| the cookie from being sent to you if it can not be done securely.
|
*/

'secure' => false,

]; ``

via Chebli Mohamed