Keys not working

This has been happening more and more. I'll get into a game, and none of my keys will register. Can't lock camera, can't ping, can't use summoner spells or abilities, can't do anything. Used to be I could DC and come back and that would fix it. But last time I tried it 5 times and it did nothing. Tried resetting keys, did nothing. It's getting on my nerves. And getting me in AFK trouble.