Option 1: take it in and have the Geniuses look at it
Option 2:
On my 2011 MBP I cleaned this with a little water. I popped off the keys and soaked them in water and then uses a damp q-tip to clean the shaft that moves when the key pushes down. There were lot of videos on YouTube about cleaning keys. FWIW, the space bar, tab, and return were a little different from the other keys.
I am not sure how to remove keys and clean them on a 2016. Maybe someone has something on YouTube. Or if you are brave you can post the first video.
FWIW, I now never have food or drink near my laptop.