This may have been a request for yesterday, but I find Libby's Sauna in Stratford open all night. And there are others in the area if you search 'massage' on Google.
Never ventured to Libbys any good
A few years back I paid my tenner for entry, saw the line up and chose the sole English speaker (curvy South African with specs in a basque, slightly more mature than the glum EEs in undies who formed the rest the line up) and went in the room with her. As I recall what she wanted was absurd so I put it down to experience and left a tenner lighter. She said that was the going rate and if I ever came back I'd not get it for less. I don't recall the figure but it was something like £80 for a 15 minute 'massage' and fuck (most East London saunas back then were £10 + 40 for that, with much younger girls too).