The important thing on this level is that you make sure to use the colour bomb to hit the red candies when it is released once the first key two key have gone. After that try to get the remaining keys as quickly as possible and then try to get all the liquorice.
The key levels are easily manipulated and can be frustrating, so if they don't drop fast enough it's best to wait for a lucky board. I got mine just now on my fourth try. It should be possible to do with a bit of patience. Good luck.