The documentation for Magento 2.4 system requirements is not clear.
https://devdocs.magento.com/guides/v2.4/install-gde/system-requirements.html#database says that it is compatible but not tested.
Not tested indicates that it is not supported?
I tried Magento 2.4 on MYSQL 5.7 and it's still working fine.
I'm not sure about the latest version 2.4.2 but I guess it should still work fine with Mysql 5.7.
