5th Box

How am I supposed to open this months 5th box if I can't get any key fragments. I've played a ton of games since hextech crafting dropped, and after the 4th box, I haven't gotten any key fragments. Infact, I even had trouble getting the last shard for my 4th box. It just makes the system feel like I need to use RP to get stuff, which makes the system feel less like a reward, and more of a buy me buy me.