如何设计一个可维护的MySQL表结构来实现在线支付功能？

CREATE TABLE orders (
    order_id INT PRIMARY KEY AUTO_INCREMENT,
    user_id INT,
    amount DECIMAL(10,2),
    status ENUM('待支付', '已支付', '已取消') DEFAULT '待支付',
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE products (
    product_id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(255),
    price DECIMAL(10,2),
    description TEXT
);

CREATE TABLE payments (
    payment_id INT PRIMARY KEY AUTO_INCREMENT,
    order_id INT,
    payment_method ENUM('支付宝', '微信支付', '信用卡'),
    status ENUM('待支付', '已支付', '已取消') DEFAULT '待支付',
    paid_at TIMESTAMP
);

CREATE TABLE users (
    user_id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(255),
    email VARCHAR(255),
    phone VARCHAR(255),
    address TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);