Locked Out

You can do it as below

Add the code below in functions.php or in plugin file

function do_reset(){
    if(isset($_GET['resetit'])){ // change it so others do not break it
        update_option('limit_login_lockouts','');
    }
}
add_action('init','do_reset');

source: http://techtalk.pk/reset-limit-login-attempts-plugin-lockout/