Where Can I Find T3 Exterminate Keys?

[FATEdPondera]

So, I've been trying to get the Nyx prime chassis, and no one appears to be running those missions in recruitment, and the chassis itself is not being sold in trade. Even if it was, I imagine it would be insanely expensive. So, that leaves farming for it myself, and I'm having some troubles.

 

I've been slaughtering my way through the outer terminus and Narcissus for the past couple days and have not seen a single key drop. I'd heard some rumors that excavation on earth had some T3's but that seems unlikely, considering their levels.

 

So, did the drop table change with the most recent update? where can I find T3 exterminate keys?

[trieuazn0]

ive heard that the excavation reward tables has changed as of u15, but prior to u15, the excavation on Phobos and Neptune gave out alot of t2/ t3 keys. you could try ur luck there or at Europa

[Goblin_Wizard]

As usual Survivals Tier 2,3 give T2 and T3 keys. Interception on Saturn too but unfortunately I haven't find a place that drops T3 keys only.

[GinKenshin]

I just played 2 sur missions on elara, jupiter and got 2 t3 ext key 

[Nerva2009]

defense on pluto at wave 20, so far always reward t3 keys for me