If you take the keyboard out you could frankly slosh it around in water (not soapy unless very well rinsed), let it dry (it will probably take a few hours, but give it a day in rice to be sure) then try it again. Pure alcohol would be best, but not cheap and you might as well just buy a new keyboard.
You'll be able to buy a new keyboard for £15-25.
You'll be very lucky if none of the drink made it around the keyboard and onto the motherboard. If you have doubts it's more than the keyboard causing any problems plug in a USB keyboard and/or mouse to test.