Anywhere, at the speed of light.
Pick any two places. The page computes the light-time floor between them, how close each real route comes to it, and what a secure message or a teleported qubit adds on top. Banking key and entanglement before the message exists is what brings both down to the floor, wherever the two ends are. The physics is qll/space/latency_floor.py, ported line by line to docs/js/latency_core.js and checked against it for every pair of places.
What physics allows. Nothing outruns light: d/c is a hard floor. Entanglement does not beat it either, because whatever Alice does to her half of a pair, Bob sees nothing new until a classical message arrives (the no-signalling theorem). "Almost instantaneous" therefore means one trip at the floor, with nothing waiting on top. On Earth that is at most 67 ms; to the Moon about 1.3 s; to Mars 3 to 22 minutes.
The geometry of the floor
The numbers
Every route against the floor
A pulse down every route
When can it be read?
On the fastest route. Banked key or banked pairs need one trip; key made on demand needs three, and a fresh internet connection with TLS 1.3 five.