Where is the Cigarette Lighter Socket fuse for 2015 FIT EX???
 

So there are 3 different "stages" of power from what I can tell, I'll refer to them as "ALWAYS ON", "ACCESSORY", and "VEHICLE ON". The first is self explanatory, "ACCESSORY" is the first push of the push to start button, and "VEHICLE ON" is the second push of the push to start button.

I plugged a USB charger into the front cigarette lighter socket to determine which stage of power the socket is on for. My quick test showed for the ACCESSORY and VEHICLE ON stages.

So looking at the Engine Compartment Fuse Box A and B tables, none of these descriptions seem to point to the Cigarette Lighter Sockets.

Looking at the Interior Fuse Box A and B tables, here are the fuses I would suspect protect this circuit and why I don't think they do:

Fuse Box A:
#17 - ACC Socket (Console) 20 A - There's not even a fuse installed here in my car.
#36 - Front ACC Socket 20 A - Meter shows there's only voltage here at VEHICLE ON
#37 - ACC 7.5 A - Meter shows there's only voltage here at VEHICLE ON

Fuse Box B:
#10 - ACC Socket (Console) 20 A - Meter shows this is ALWAYS ON

Am I missing something here?

What am I missing? You said there isn't a fuse for the ACC, but you said there is a fuse at 36,37, and 10 because they are working, but not to your reasoning.. Could there be a delay before it powers off? For example, the power windows works a bit after you turn off the power.

Inside, driver's side- there are two fuse boxes. One where fuses are plainly visible. (This isn't it) Another just below with a black cover. Use a anything about the size of a toothpick to remove the cover. Then on the bottom row, 2nd from the right is a Yellow 20A fuse that serves this Accessory Socket inside towards the back of the center console. (#10 if you look inside the cover and see the fuse map) If you need a fuse removal tool, under the hood in the lid of the fuse box in the driver's side near the firewall, you will find a fuse removal and installer tool.