Good Missions For T2 Keys?

[PurpleBomber]

I'm running kinda low on T2 void keys, and after thinking on it, I'm not really sure what a good way to farm them is. Apollodorus tosses you a T1 key easily enough and you can do pretty much any high-level defense or survival for a T3, but T2 at least to me seems to be in an awkward middle ground. I've been doing a lot of Cambria, Earth for mod hunting, but that seems to give a T3 key just as often as a T2, which is kinda... eh. So are there particular missions where T2s are pretty much guaranteed at the 15 min/wave mark?

[Angius]

ODD/ODS

[Archistopheles]

If you don't want to waste money, you can also do mid level planets like Earth and Jupiter.

 

I also seem them from Eris quite often too.