Dungeon World uses Dexterity. When you Defy Danger (DW's equivalent of Act Under Fire) by getting out of the way or acting fast, you roll +Dex. (Dex is also grace, agility, accuracy, etc., so it's used for Volley, picking locks, etc.). Beyond that, there are also moves in DW like the Thief's Shoot First (you are never surprised; when someone would get the drop on you, you act first).
Basic moves represent the things you're interested in seeing the PCs do, while the stats represent the different ways you're interested in the PCs being (and how they are different from each other). The way they interact is your observation about those character traits and the things the characters do.
So (assuming you're still talking about your In Nomine hack), I'd ask yourself whether you're actually interested in how physically quick one celestial is vs. another. Or could such quickness be boiled down to something like "Sharp" or "Accuity" or "Wits" that represents speed of thought?
Also, is there a basic move (or set of moves) where you see that quickness being important? If not, this is all kind of a moot point.
Final thought: the basic moves don't have to be tied to a specific stat. I've been working on a hack in which the moves themselves are potentially broader than in most hacks, but they aren't tied to the stats. The moves have clear fictional triggers, but the way in which you describe hitting that trigger influences which stat you roll. For example:
When you attack your enemy from a position of strength or safety, roll to assault. On a 10+, inflict harm as established and choose one...
When you chase, follow, or track down your quarry, roll to pursue. On a 10+ you corner your prey or catch them in the open. On a 7-9...
If you assault someone by drawing a bead and sniping them, roll +Cool to do it. If you assualt a group by casting fireball, roll +Magic. If you assault a dude by bashing a chair over his head from behind, roll +Brawn.
If you pursue someone by running after them through the streets, roll +Grace. If you pursue someone by following their tracks through the woods, roll +Wits. If you pursue someone by asking around in town, roll +Presence.
To tie this back to your question: if you take an approach to your moves that doesn't explicitly tie them to your stats, then whenever someone triggers a move you can look to the fiction to see which stat is most appropriate. In which case, "Speed" is only a stat if you think it's important enough differentiator to be one. Otherwsie, you can look to whatever stat is most appropriate to the fictional situation (and if you're a fan of the characters, you'll be generous about the corner cases).