So i contacted Microsoft support who said that if a laptop had any water damage, they would refuse to repair it and simply send it back. Even for a fee. Which in my opinion is pretty weak for such a large corporation to refuse to offer repair services.
My solution? As the keys were only sticky and the laptop is still functional, i managed to take the keys off one by one, clean them with isopropyl alcohol and stick them back in.
The keys are no longer sticky and the laptop works as good as new.
Don't think i'd buy another surface after this..