It's considerably heavier than a standard imposed load, but whether or not the floor would b overstressed depends on a number of factors.
The fact that you plan to put the tank near the edge of the floor and it's only a small area means that it may well be OK, but in reality it's impossible to say without more information.
All we know is that the floor is concrete. Concrete floors vary considerably (Type [beam and block, filler joist, planks, cast in-situ], depth. reinforcement]. We don't know the span, or the span direction. Does the stand impart point loads to the floor? Gut feeling is that it would be OK but you need an engineer to come out and assess.