Can I trade chests for key fragments?

I am a Thresh support main that gets 'S' ranks more than the average player. I'm not bragging, that is actually relevant to what I wish to say here. Because I have so many 'S' ranks, I accumulate a LOT of key VERY VERY quickly, and no chests to use them on. (I currently have 20 full keys, and 0 Chests). Should there be a way for me to trade excess keys for a chest or two? (I.E. : Three full keys for one hextech chest). That would give me some sort of reason to strive for more 'S' ranks at this point, because right now, whenever I receive key fragments from Honors or 'S' rank, i don't even care anymore. They don't affect me at this point. Which really sucks tbh.

• DylHines