title: How to validate expiry date on MySQL query
body: <p>Here is my current mysql table</p>
  
  <pre><code>id  | file        |  expiry_date
  ---------------------------------------
  1   | sample.zip  |  2010-02-03 11:07:03
  2   | sample2.zip |  2010-07-13 11:07:03
  </code></pre>
  
  <p>Query:</p>
  
  <pre><code>SELECT * 
    FROM download 
   WHERE expiry_date` `how to validate here`
  </code></pre>
  
  <p>I want to validate if <code>expiry_date</code> is expired the file cannot download.</p>
  
  <p>How to do that?</p>