Mouse and keyboard stop working in middle of the game.

So this started a few days ago, I was just simply playing a RANKED league game. Suddenly, my cursor freezed right there, my keyboard wasnt working, like it have turned off. I pressed alt+tab or alt+f4, but nothing worked. I restarted the PC from that button next to the power button on my PC. When I got to the windows screen, my keyboard was working, but my mouse cursor wasnt there, i unplugged and plugged my mouse and my cursor appeared. I re-entered the game and everything was ok. But this is starting to happen more often through the days... I haven't any viruses or anything like that, I haven't downloaded any type of unusual things, just playing league. Does anyone know a fix to this??