Protection in Ajax request with php

I created a page, where I use the post method with Jquery for another, and return some calculations.

Trying to protect, I did the following on the page:

INDEX PAGE:

PHP

<?php

    session_name('ola');
    $secure = false;
    $httponly = true;
    ini_set('session.use_only_cookies', 1);
    $cookieParams = session_get_cookie_params();
    session_set_cookie_params($cookieParams["lifetime"], $cookieParams["path"],     $cookieParams["domain"], $secure, $httponly);
    session_start();
    $_SESSION['_token'] =  hash('sha512', rand(100, 1000).time().'ola');    
?>

HTML

<input type="hidden" name="token" value="<?php echo $_SESSION['_token']; ?>" />

JQUERY

$.post("php/infowindows.php", {token : $("[name=token]").val()}, function(d){
            alert(d);       
});

PAGE CALCULATIONS:

<?php
    session_name('ola');
    session_start();
    if(!isset($_SESSION['_token']) or !isset($_POST['token']) or $_POST['token'] !== $_SESSION['_token']){
        die("Erro, morri!");
    }
    session_regenerate_id();
?>

I saw some posts, so I decided to create my own code. In front of this, is it possible to say that he is "preventing" against CSRF attacks?