Get random row from MySQL table

I'm trying to fetch a random row from a table in MySQL. I'm using the following query:

SELECT *
FROM my_table
WHERE id IN (
    SELECT ROUND((RAND() * (MAX(id)-MIN(id)))+MIN(id)) AS id
    FROM my_table
);

I wish to understand why that query sometimes returns more than 1 row when the inner query always get 1 row?

Thanks