A good easy and quick way of covering up scabs on your face is to use some concealer that you can buy in the makeup aisle of Walmart or of any other stores.
Take some concealer and put it on your finger and gently dab the concealer over the scab but be sure to not rub the concealer in and just dab the concealer over the scab.
Continue dabbing some concealer on the scab until you've built up a few layers of the concealer on the scab.
Then let the concealer dry on the scab and then use a makeup sponge to apply some liquid foundation to the concealer and then you should no longer be able to see the scab or at least it should be less visible.