Get related columns depending on a ID
You could change the query slightly so that the exclusion is done within the join:

SELECT DISTINCT aj2.article_id, aj2.tag_id
  FROM article_tag_join AS aj
  JOIN article_tag_join AS aj2
    ON aj.tag_id = aj2.tag_id
   AND aj.article_id &lt;&gt; aj2.article_id
 WHERE aj.article_id = 75;


This might offer better performance, but it is always worth comparing it against your existing query. If I have two queries that result in the same execution plan, I pick the one that is easiest to maintain.