Sometime I can click on the button, sometime doesn't work

I am trying to click on a button if an element is found on the page. The element is on the page most of the time. 3 times work, and 1 time doesn't work. Here is my code:

elements = driver.find_elements_by_xpath("//h2[contains(text(),'No results found')]")
if (len(elements)>0):
    WebDriverWait(driver, 30).until(EC.element_to_be_clickable((By.CLASS_NAME, 'ut-navigation-button-control'))).click()
else:
    WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.XPATH, "//button[contains(., 'Buy Now')]"))).click()

And below is the error I get sometime:

ElementClickInterceptedException: Message: Element <button class="ut-navigation-button-control"> is not clickable at point (128,80) because another element <div class="ut-click-shield showing interaction"> obscures it

    try:
        WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.XPATH, "//button[contains(., 'Buy Now')]"))).click()
    except:
        WebDriverWait(driver, 30).until(EC.element_to_be_clickable((By.CLASS_NAME, 'ut-navigation-button-control'))).click()

It's working like this, but it take a lot of time during the except. Does anyone know how to make it to go quickly through except?