I have been digging deep to try and find the answer here and on Google...hopefully someone can help.
What I am trying to do is connect to MySQL from a Google Spreadshee
Sigh...The solution was right in front of my face. I needed to grant the Google App Server IPs. Im sure you could add more code to connect over ssh and its more secure but this is fine for now.
Here are IP address range:
216.239.32.0 - 216.239.63.255 64.233.160.0 - 64.233.191.255 66.249.80.0 - 66.249.95.255 72.14.192.0 - 72.14.255.255 209.85.128.0 - 209.85.255.255 66.102.0.0 - 66.102.15.255 74.125.0.0 - 74.125.255.255 64.18.0.0 - 64.18.15.255 207.126.144.0 - 207.126.159.255 173.194.0.0 - 173.194.255.255
https://developers.google.com/apps-script/jdbc#accessing_local_databases