    <?php 
          $array = array
                    (
                      array
                          (
                           'uid' => '100',
                           'name' => 'Sandra Shush',
                           'url' => 'urlof100'
                      ),
                      array
                          (
                           'uid' => '5465',
                           'name' => 'Stefanie Mcmohn',
                           'url' => 'urlof100'
                           ),
                      array
                           (
                            'uid' => '40489',
                            'name' => 'Michael',
                            'url' => 'urlof40489'
                           )
                   );
    
    $key = array_search(40489, array_column($array, 'uid')); 

    

    if($key != null && !empty($key))
        echo $array[$key]['name'];
    else
        echo "sem dados";