You may want to detach the keys in order to give the keyboard a thorough clean-up.
When you have removed the keys, soak them in a bowl of warm soapy water for a few minutes.
Meanwhile, clean the keyboard with a can of compressed air.
Check if the keys are completely dry.
Place the keys back one by one on the keyboard.
Cleaning your laptop keyboard must be done on a regular basis, to ensure top performance of your machine all the time.