That wound is serious enough (and placed badly enough) that I would recommend having a veterinarian look at it. For more minor wounds, you can disinfect with betadine (a type of iodine). Never use any antibiotic ointments that contain pain killers. Some antibiotics are not safe for reptiles, and the pain killers placed in them are not either.

The snake will probably be ok if the wound is cleaned and disinfected, but it's much better to be on the safe side, since it's in such a delicate area.