So assume you just uploaded the certificate you use to identify
yourself to the MySQL server to Github or some other place it
doesn't belong...and there is no undelete.
First: Don't panic.
Often a password is required besides a certificate to connect to the server. So someone with the certificate can't use it without the password. The certificate itself might be protected by a password, but that's really rare. Also access to MySQL and/or your account should be limited to certain IP's.