MySQL 5.7 Community Server End of Life/Support
As per MySQL documentation here the below you can find the life cycle for each version of application MySQL

Current releases

Release        Release date              End of life

MySQL 8.0      April 19, 2018       
MySQL 5.7      October 21, 2015          October 21, 2023   
MySQL 5.6      February 5, 2013          February 5, 2021   


All releases

Release        Release Date            End of life  

MySQL 8.0      April 19, 2018       
MySQL 5.7      October 21, 2015       October 21, 2023  
MySQL 5.6      February 5, 2013       February 5, 2021  
MySQL 5.5      December 3, 2010       December 3, 2018  
MySQL 5.1      November 14, 2008      December 31, 2013 
MySQL 5.0                             January 9, 2012


For further your ref here and here