Expired timestamp, yours 1523889045, ours 1537740910
<hr />
OAuthRequest Object
(
    [parameters:protected] => Array
        (
            [oauth_consumer_key] => key
            [oauth_nonce] => 4295d7376a23fb96939edd2939d50048
            [oauth_signature] => 1xAOT+Jj66xjqTijr2z8DY/riKI=
            [oauth_signature_method] => HMAC-SHA1
            [oauth_timestamp] => 1523889045
            [oauth_token] => requestkey
            [oauth_version] => 1.0
        )

    [http_method:protected] => GET
    [http_url:protected] => http://oauthbin.com:/v1/access-token?oauth_consumer_key=key&oauth_nonce=4295d7376a23fb96939edd2939d50048&oauth_signature=1xAOT%2BJj66xjqTijr2z8DY%2FriKI%3D&oauth_signature_method=HMAC-SHA1&oauth_timestamp=1523889045&oauth_token=requestkey&oauth_version=1.0
    [base_string] => 
)