PdoMysql.php

namespace KeyRotate;

use Doctrine\Common\Cache\PhpFileCache;
use Doctrine\DBAL\Driver\PDOMySql\Driver;

class PdoMysql extends Driver
{
  protected $client;
  protected $cache;

  /**
   * Cannot add a constructor with params, since it's called in DBAL's drivermanager like:
   *      $className = $params['driverClass'] ?? self::$_driverMap[$params['driver']];
   *      $driver = new $className();
   */
  function __construct($client, $cache) {
  }
}

test.php

<?php

use Doctrine\DBAL\DriverManager;

$connectionParams = [
    'dbname' => 'mysql',
    'user' => '/secret/database-2',
    'password' => '', //fetched from
    'host' => 'mijn.rds.eu-west-1.rds.amazonaws.com',
    'driverClass' => KeyRotate\PdoMysql::class,
];

$conn = DriverManager::getConnection($connectionParams);

while (true) {
    sleep(1);

    $result = $conn->query("SELECT 1")->execute();
    print_r($result);
}