CREATE TABLE IF NOT EXISTS `rate_limits` (
  `id` INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  `cache_key` VARCHAR(255) NOT NULL,
  `attempts` INT UNSIGNED DEFAULT 1,
  `window_start` INT UNSIGNED NOT NULL,
  `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  `updated_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  UNIQUE KEY `uk_cache_key` (`cache_key`)
) ENGINE=InnoDB;