blue-twilight/app/Http/Controllers/Auth/ActivateController.php

<?php

namespace App\Http\Controllers\Auth;

use App\Http\Controllers\Controller;
use App\User;
use Illuminate\Foundation\Auth\RedirectsUsers;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\App;

class ActivateController extends Controller
{
    use RedirectsUsers;

    /**
     * Where to redirect users after activation.
     *
     * @var string
     */
    protected $redirectTo = '/login';

    /**
     * Create a new controller instance.
     *
     * @return void
     */
    public function __construct()
    {
        $this->middleware('guest');
    }

    public function activate(Request $request, $token)
    {
        /** @var User $user */
        $user = User::where(['is_activated' => false, 'activation_token' => $token])->first();

        if (is_null($user))
        {
            App::abort(404);
            return null;
        }

        $user->is_activated = true;
        $user->activation_token = null;
        $user->save();

        $request->session()->flash('info', trans('auth.account_activated_message'));

        return redirect($this->redirectPath());
    }
}