Is my word count below the accepted word count?
Question: I read the word count for Fantasy is around 75k + and it's so because of world building.
My story is MG and it's around 24500, is it too small, considering the fact that 90 percent of the story is set on earth where only three people know and use magic?Answer:
You have to take recommended word counts as guidelines, not law. You are on safer ground if you follow them, but there are exceptions.
Middle-grade novels are generally shorter than adult novels, particularly if you are aiming at the low-end. Kids who are weaker readers might be turned off by a full-length novel, and yet they still want a story that appeals to their age group, rather than a chapter book.
If, as you say, your book is set on earth in the present time then obviously you have less world-building to do, though the reader may still need some explanation of these magical characters.
So while your book is a little short (if it were an adult book, it would be classified as a novella), it might not be fatally short. It depends on the quality of the writing. If the plot and characters are engaging, if the vocabulary is appropriate for weaker readers, and if the editor doesn't find a lot that needs to be cut, you might be all right. You might find a publisher looking for "easy reader" books. On the other hand, an editor might suggest you develop some characters or plot lines a bit - but only if he really likes what you already have written.