How to optimize report queries
<p>I studied here and there but i couldn't find a way to optimize this query.</p>

<pre><code>SELECT  ad_request.user_id,
    ads.req_id,
    ads.id as doneId 
FROM ads
    INNER JOIN ad_request ON ads.req_id = ad_request.req_id 
WHERE 
    (ads.user_id='3612185701') AND ads.date&gt;DATE_ADD(NOW(),INTERVAL -4 DAY) 
ORDER BY ads.id
</code></pre>

<p>Query Digest:</p>

<pre><code># Attribute    pct   total     min     max     avg     95%  stddev  median
# ============ === ======= ======= ======= ======= ======= ======= =======
# Count          0     836
# Exec time     17    322s   481us     11s   385ms      2s   956ms    51ms
# Lock time      0   203ms   103us    23ms   242us   332us   787us   185us
# Rows sent     67 209.30k       0   3.56k  256.36   1.46k  478.03    1.96
# Rows examine   1 1021.57k       0  55.08k   1.22k   4.71k   3.05k  202.40
# Rows affecte   0       0       0       0       0       0       0       0
# Query size     0 218.29k     262     268  267.38  258.32       0  258.32
</code></pre>

<p>the digest is just from a 30-minute frame , sometimes several instances of this query get stuck for +100 sec</p>