+1

Consider it baptized and move on. If you ride at all seriously, this will soon be the smallest blemish on your frame.

If it bothers you you can polish it out a bit with automotive rubbing compound which will camouflage it a bit. If it's through to bare metal you could use a bit of touch up paint, or nail polish to protect the exposed metal.

Odds are you'll continue to see abrasion from your lock, and since you now know where it'll be, you can protect the area from further cosmetic damage with clear protective tape. They sell clear film with a low tack adhesive, for things like chainstays (gets clobbered by the chain) and head tubes where flexing cables rub.

Or you can be like Kimmo and myself and proudly ride a bike with character lines. (what a woman whose lived a full life calls wrinkles).