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 (220.127.116.11) and remote DB instance (18.104.22.168) listening port 3306
$ ssh -L 3307:22.214.171.124:3306 email@example.com
Testing ssh tunnel
$ telnet 127.0.0.1 3307
$ # or
$ mysql -h 127.0.0.1 -P 3307 -u root -p