Up arrow key not working after cleaning

Your in bit of a pickle here ;-{ As NDJenny said you need to dampen the micro-cloth with a mild cleaner like Fantastic for sure nothing with grit or a polish as they leave a grit or a film.

You appear to have gotten the cleaner inside the keyboard. Now the issue is how deep and if you can clean it out (hopefully it hasn't caused any corrosion or other damage).

The key caps can be pulled off (snap-on), otherwise taking the keyboard apart will be risky as it's glued together.

Try taking the keys off (the key in question and the surrounding keys) and using a non-lubracating electronics cleaner spray (alcohol type) try a small blast to try cleaning any residue that could be left and drying it out. Make sure to tilt the keyboard so the junk doesn't wash over the other key areas. - Good Luck!