Admittedly this is a low-quality question as well, but the answer came up in my review queue as having been marked as low-quality. From what I can tell, the answer provided has a legitimate chance to solve the asker's problem. That makes it an acceptable answer, in my opinion.
However, the OP commented to say that it didn't work. Without additional information from the asker or answerer, it is difficult to judge the underlying quality or accuracy of the answer. The answer could admittedly be improved by explaining what the asker might be doing wrong and what the provided code does to address that. The critical distinction is that the answer isn't wrong, it just doesn't solve (all of) the asker's problems.
What should a reviewer do in a situation like this? My reaction is to mark it "Looks good." This is partially informed by my knowledge of PHP and MySQL. If the question were about something I had no special knowledge of, I would be inclined to skip the review.