First, use jQuery.parseHTML to parse the HTML into an array of elements; then you’ll be able to convert it to a jQuery collection and use filter to restrict the collection to elements matching a selector.
var html="<td class="test">asd</td>" +
'<td class="second">fgh</td>' +
'<td class="last">jkl</td>';
var text = $($.parseHTML(html)).filter('.test').text();
console.log(text);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>