Problema com migration, usuário retorno null ao invés de vazio

Pessoal se alguém puder me ajudar, eu travei bonito nessa parte, já revisei várias vezes a aula mas não tá rolando.

Esses são os fontes que escrevi baseados na aula:

TokenController.php

<?php

namespace App\Http\Controllers;

use App\Models\User;
use Firebase\JWT\JWT;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Hash;

class TokenController extends Controller // Extende Controller para ter acesso ao método validate() no $this
{
    public function gerarToken (Request $request)
    {
        // Garante que os dados estão na requisição
        $this->validate($request, [
            'email' => 'required|email',
            'password' => 'required'
        ]);

        // Faz a query e pega o primeiro resultado
        $usuario = User::where(['email', $request->email])->first();

        if (is_null($usuario) || !Hash::check($request->password, $usuario->password)) {
            return response()->json('Usuário ou senha inválidos.', 401);
        }

        $token = JWT::encode(
            ['email' => $request->email],
            env('JWT_KEY')
        );

        return [
            'access_token' => $token
        ];
    }
}

a migration criar_tabela_usuarios

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CriarTabelaUsuarios extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('usuarios', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('email')->unique();
            $table->string('password');

            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('usuarios');
    }
}

A model User.php:

<?php

namespace App\Models;

use Illuminate\Auth\Authenticatable;
use Illuminate\Contracts\Auth\Access\Authorizable as AuthorizableContract;
use Illuminate\Contracts\Auth\Authenticatable as AuthenticatableContract;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Laravel\Lumen\Auth\Authorizable;

class User extends Model implements AuthenticatableContract, AuthorizableContract
{
    use Authenticatable, Authorizable, HasFactory;

    protected $table = 'usuarios';

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'email',
    ];

    /**
     * The attributes excluded from the model's JSON form.
     *
     * @var array
     */
    protected $hidden = [
        'password',
    ];
}