I think its obviously harder the older you get. You can have a baby face at 25 that makes you look like a high school kid still. Its harder to look 30 at 40-45!
That said. My mom is late 50s and people generally assume she is just turned 50-ish. So some aging down is possible. Its just good genetics. Luck of the draw.
I'm 33, definitely don't look 23 even though I have no greys, lines or wrinkles at all yet (thanks mom!)- there is just a different look to youth sometimes that you can't pinpoint. I think its more possible to look ambiguous and that's probably your best case scenario

For example, I probably look anywhere between 27 and 33. I'll take it.