Selenium can't click element because other element obscures it

There are several ways to do this, one of the ways is by Javascript executor.

You could say:

element = driver.find_element_by_xpath("//div[@class='blockUI blockOverlay']")

driver.execute_script("arguments[0].style.visibility='hidden'", element)

This way, you can block the div with class = 'blockUI blockOverlay' and your element can be clicked if I'm correct.

Following nr.5 of DebanjanB's answer, I solved it by implying the code to wait for the temporary overlay to dissapear before trying to click,

wait.until(EC.invisibility_of_element_located((By.XPATH,
              "//div[@class='blockUI blockOverlay']")))
el_xp("//input[@value='Save']").click()