The keys on a laptop keyboard are different from a standard keyboard and they usually cannot be removed. So, to clean this, use the same damp cotton cloth you used to clean the exterior of your laptop. Just wipe the cloth over the keys and some of the dust and dirt particles will be removed. You can also use compressed air to get some of the debris out from in and around the keys.
It's a very good idea to clean your laptop's touchpad every once in awhile. It can help your laptop to look new, as well as, improve the quality of the motion and response of the touchpad. You can use the same damp cloth to clean this one too. Just run the cloth over the touchpad area and make sure you squeeze in around the corners to catch any debris that may be sitting there.