Laravel Set time for specific session variable.

if (Session::get('LAST_ACTIVITY') && (time() - Session::get('LAST_ACTIVITY') > 60 )){
             
            $validMerchant=Merchant::where(['id'=>Session::get('merchantId'),'status'=>1])->first();
            if ($validMerchant!=NULL) {
                return $next($request);
            }
            return redirect('/');  
         }
         return redirect('merchant/login');