Please timely renew your RDS for MySQL to avoid loss due to instance expiration.
Renewing
When the subscribed database instance expires, the corresponding database service is suspended. Your application cannot access the database service. At this point, you can extend the expiration time of the instance through renewal. For more information, see Instance Management-Renewal.
Unsubscribe
When the subscribed database instance expires, the corresponding database service is suspended. Your application cannot access the database service. You can also unsubscribe from an unexpired instance by manually doing so. For more information, see Instance Management-Unsubscribing.