May Allah and Imam accept your Ziyarat. It’s not an obligatory that you must touch or kiss the Zarih your Ziyarat is complete one you entered in the Holy shrine of a Masoom (a.s) and seen the Zarih but if it’s possible for you to wait few hours where you can get the chance to touch the Zarih it’s better to do so. I know at the holy Sharib’s of Imam Reza (a.s) it’s not easy to go near the Zarih but if you wait and near the Namaz time it get bit less crowded then you can reach to the Zarih. Otherwise it’s ok don’t worry.