Issue while trying to access Moodle restful web service

URL:

http://localhost/moodle/webservice/rest/server.php/?wstoken='c05f1bf389c771a41736aed9443a9620'&wsfunction='core_course_get_courses'

content type: application/json

method: GET

Result:

<?xml version="1.0" encoding="UTF-8" ?>

<EXCEPTION class="moodle_exception">

    <ERRORCODE>invalidtoken</ERRORCODE>

    <MESSAGE>Invalid token - token not found</MESSAGE>

</EXCEPTION>

I am getting the following exception if I try to access moodle restful api, I have done all the initial setup required to access the restful api's .

I any one have solution for this please let me know through this post.