I am currently running MediaWiki 1.25.3 and planning to upgrade. I was concerned by the MySQL table which looks like I need to change MySQL versions when going from MediaWiki 1.29 to version 1.30. But the table seems to be mistaken, because when I look at my wiki's version page I see: MySQL 5.7.25-log so it seems that the MySQL 5.5.8+ box needs to be much longer in the MySQL table.
Topic on Talk:Compatibility
Under MW 1.25, the table says "MySQL 5.0.3+" which means older versions are unsupported (but might unofficially work), and newer versions are supported and are expected to work. That includes MySQL 5.7.
The change between MW 1.29 and MW 1.30 is that MySQL 5.4 and older are no longer supported and might not work.