CREATE TABLE IF NOT EXISTS `otp_codes` (
    `id` INT AUTO_INCREMENT PRIMARY KEY,
    `email` VARCHAR(255) NOT NULL,
    `code_hash` VARCHAR(255) NOT NULL,
    `created_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `expires_at` TIMESTAMP NOT NULL,
    `is_used` BOOLEAN NOT NULL DEFAULT FALSE,
    INDEX `email_index` (`email`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;