SSH Tunnel is a fast way to transfer traffic through unsafe internet today. It would be used in MySQL connect, FTP connect or HTTP connect, ...
$ ssh -L [local_port]:[remote_endpoint]:[remote_port] [ssh_user]:[ssh_ip]
Lets say you have a EC2 instance (126.96.36.199) and remote DB instance (188.8.131.52) listening port 3306
$ ssh -L 3307:184.108.40.206:3306 firstname.lastname@example.org
Testing ssh tunnel
$ telnet 127.0.0.1 3307
$ # or
$ mysql -h 127.0.0.1 -P 3307 -u root -p