Error in your SQL syntax, check the manual

Question

I have the following SQL query:

$query="
    SELECT post_id,FIND_IN_SET(
        post_id,(SELECT GROUP_CONCAT( post_id ORDER BY meta_value * 1 DESC)
             FROM $wpdb->postmeta
             WHERE meta_key ='ma_ratings_average')
        ) AS rank
    FROM $wpdb->postmeta
    WHERE meta_key ='ma_ratings_average'
    AND post_id = '".$post_id."'
";

And since upgrading to MySQL 8, I am getting this error:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'rank FROM wp_postmeta WHERE meta_key ='ma_ratings_average'

What does this mean and what's the route to resolve it?