The [MYSQL] interface does not support specifying a certificate.
It looks like the MySQL ODBC driver does have options for specifying a certificate. So I would suggest using the ODBC driver and creating a DSN with your SSL certificate set and the [ODB] interface to connect using that DSN.
Often when making a SSL/TLS connection only the server needs to specify a certificate and the client just validates it. I believe for MySQL it is the same and you can connect to a SSL/TLS secured MySQL using [MySQL] without specifying a certificate (with default MySQL server settings). So it is possible you don't need to worry about specifying the certificate. Of course your MySQL server may be setup to require it and if that is the case then you will want to use the ODBC driver so you can specify those options.