I have exactly what you need, already programmed myself from the ground up (including an installer with key check built in for any EA, script, etc., PHP scripts on the web side to manage the keys, and scripts you can use to add keys, remove keys, disable keys, etc). I've coded this for use with the software I release to the public, giving me total control over everybody who uses the software. I am able to cut off access to any specific key at any time, and have automatic scripts embedded into Infusionsoft to do this auotmatically as people are added or removed from my continuity program.
If this interests you, I can set you up with a FULL turn key solution, and help you install and support it. Let me know, and I'll start getting everything set up for you.