Maybe something like this can help. Do a check on the userid and the time before you insert the data. You would need make sure to do a search on database fields that are unique (unless the time field is the full time)
$data=array(
'userid' => $userid,
'email' => $email_data,
'phone' => $this->input->post('phone'),
'discount' => $this->input->post('discount'),
'price' => $this->input->post('price'),
'final_price' => $this->input->post('final_price'),
'client_data' => $this->input->post('client_info'),
'client_ip' => $this->input->post('client_ip'),
'time' => $date
);
if (<!--CONDITIONAL STATEMENT-->)
{
$this->db->insert('orders_temp', $data);
}