Up close it doesn't look very realistic, you can tell it's fake, but from the distance, and through the camera it will look realistic. If there's gonna be a close up of the scar, then you should try add some more detail, but if there's gonna be no close up, it's ok, no need to do anything else.
The thing that threw me off was that the cut looks fresh, the blood is still bright red, yet, nothing is flowing out. If you cut your cheek open the way that looks, you'd have blood streaming out like there's no tomorrow.
try adding a little more pink colored irritation around the cut. i do SFX makeup in my free time as a fun little hobby. google some facial cuts and use that as a reference photo. there are also a lot of youtube tutorials for it. thats how i learned!