Edit in JSFiddle

<p>pointer-events: none to select element</p>
<select name="" id="" style="pointer-events: none">
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
</select>

<hr>

<p>pointer-events: none to select's <b>parent</b> element</p>
<div style="pointer-events: none">
  <select name="" id="">
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
  </select>
</div>