What games count towards hextech crafting keys?

ARAM counts towards getting keys since any matchmade win has a chance of giving you a key. Getting a good mastery score doesn't increase your likelihood of earning a key, but being part of a premade does.

Edit: At least that's my understanding.

I doubt bots count, and it's not likely that ARAM counts either since it doesn't have a mastery thing going on.

Matchmade. I assume ARAM does. Bot probably not? I don't know. The thing with ARAM though is it's harder to get an S I would imagine.

Riot's support articles list everything except for custom games as "matchmade games." So ARAM and Co-op games should both count.