spray the crumbs and dust off the keyboard with the canned air, then saturate the cotton bulb of a qtip and run it around the edges of your keys and any other nooks and crannies, then put more alcohol on a microfiber cloth and run it across your whole keyboard
i have taken the keyboard apart and cleaned it but the connections can be tricky. On th eplus side most laptop keyboards (minus apple) are inexpensive now, 30 dollars at the most, i've picked up some for 11 (depends on backlighting)
I can't remember where I got it at the moment, but there's a keyboard tool for laptops that has a silicone pointed brush at one end, great for working out dust and such in corners and crevices.
This is my main work computer at the moment so I'm not brave enough to try and take anything apart right now lol.