The obvious point to make is that the reality of these sorts of situations very rarely matches the fantasy. It's easy to see the sort of image you're building of passionate, spontaneous sex with a hot, exotic stranger. But a person's nationality or ethnicity doesn't correlate at all with how good they are in bed, or indeed how well you will click with them. Just like any sex, sex in a one night stand might not be very good. There is also generally some sort of conversation afterwards, even if you don't see each other after that point. At the same time, it might end up being just what you need even if it's not exactly the image you built up in your mind.
The key really is thinking about this practically rather than allowing the fantasy to overtake your thought process. Where are you going to meet someone to have a one night stand with? Where are you actually going to have sex with them? What boundaries do you want to set for the sex itself and how are you going to communicate those? When are you (or they) going to leave? You need to think through these things and more not just to give yourself the best chance of an enjoyable experience, but to ensure that you keep yourself safe as well. It's also an experience that probably won't be exactly as you want to be first time round, but like anything you can learn from that do things different next time (if there is a next time).
As I say, this sort of thinking is absolutely fine, and there is nothing wrong with fulfilling fantasies. Just make sure you're sensible about it, and appreciate that in practice whilst it can still be a very good experience, and perhaps even better than you expect, it's not going to play out exactly as you think when you fantasise about it.