MySQL Supported Platforms
MySQL :: Supported Platforms: MySQL Database https://www.mysql.com/support/supportedplatforms/database.html
Support Policy
Lifetime Support Policy | Oracle Support | Oracle Japan https://www.oracle.com/jp/support/lifetime-support/
Support Period
Search for “Oracle’s MySQL Releases”
Oracle Lifetime Support Policy for Technology Products Guide https://www.oracle.com/us/assets/lifetime-support-technology-069183.pdf