OP Prison : crate keys, I don't understand

Hey, how are you meant to get different keys like common rare and ultra

 

I believe you get them from the forst crate, it's a rare chance.

 

So I can get a rare key in the voter crate?

 

If it goes common,rare, then ultra yes. You can always buy them from players too

 

What @ItsSniiper said,

You should probably request a lock..​

 

All of the keys are pretty worthless unless they have value in themselves as they give so little money.