Riot never nerfed key drops - key drops are just limited per month like chests are!
A red just posted that keys get rarer and rarer each time you find a key, and reset per month.
Which means DO NOT BUY CHESTS unless you also intend on buying keys. As someone who plays A LOT, I just barely managed to unlock my 4 free chests this week (I need one more fragment). And since chests reset at one per week.... I'm going to have 4 more chests to unlock before my keys reset this month, and the keys are BARELY dropping at all at this point for me.
