Laravel 11: questionable default indexes on table password_reset_tokens

[MircoBabin]

Laravel Version

11.2

PHP Version

8.2.16

Database Driver & Version

10.4.33-MariaDB-cll-lve

Description

The password_reset_tokens table has a primary key on email and no index on token. Which is a questionable default ( see https://github.com/laravel/laravel/blob/11.x/database/migrations/0001_01_01_000000_create_users_table.php ):

        Schema::create('password_reset_tokens', function (Blueprint $table) {
            $table->string('email')->primary();
            $table->string('token');
            $table->timestamp('created_at')->nullable();
        });

1. Why is one email not allowed multiple reset tokens? Is this a deliberate consideration?
2. Why is there no index on token?
3. Why is token not the primary key? Because I would expect token to be unique and very hard guessable.
4. Maybe unrelated, but why is InnoDB not explicitly set as the default engine? Nowadays MySql 5.6 and MariaDB 10.2 use InnoDB as default storage engine. But of course my internet provider may have changed the default. Looking into the sources I found vendor/symfony/http-foundation/Session/Storage/Handler/PdoSessionHandler.php which does explicitly set InnoDB engine. So there is a precedent for explicitly using InnoDB and thereby ruling out other non-transactional engines like MyIsam.

SHOW CREATE TABLE password_reset_tokens;

CREATE TABLE `password_reset_tokens` (
 `email` varchar(255) NOT NULL,
 `token` varchar(255) NOT NULL,
 `created_at` timestamp NULL DEFAULT NULL,
 PRIMARY KEY (`email`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

Looking back in a Laravel 4.2 project, back in the day (not by me, but by my predecessor) the then called table password_reminders was created with 2014_05_26_142727_create_password_reminders_table.php. And had no primary key, just 2 indexes on email and token.

<?php

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

return new class() extends Migration {
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('password_reminders', function (Blueprint $table) {
            $table->engine = 'InnoDB';

            $table->string('email')->index();
            $table->string('token')->index();
            $table->timestamp('created_at');
        });
    }

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

Steps To Reproduce

Run php artisan migrate after a fresh Laravel 11 installation. This time updated against the latest skeleton.