2 things. What floor covering you putting over the concrete? Although you can walk in it next day and it cures over time, it takes a while to dry out. Can’t remember exactly but something like a mm/ day. Just be careful you don’t rush to get flooring down and end up mouldy!
secondly, and more importantly, what was under that concrete slab? Don’t tell us you didn’t look and just concreted over.... could have been the archaeological discovery of the millennium. Wasn’t Richard 3rd found in a car park?