Indeed so.
Others may have more specific knowledge, but I find it hard to see that it would be practical - since any key (or combination) would have to be pretty specific to a particular installation/cabinet. Particularly in the case of physical keys, that could become a horrendous exercise.
Its not done with meter boxes, but there are ways around DNO keys having to be specific to an installation, such things are necessary when DNO switchrooms are located on customer premised, theres two ways I have seen/
1) A gate is secured with a bar through the latch, the bar has a hole in each end, on one end a customer padlock is attached, and on the other end a DNO key'ed alike padlock is fitted, removing either lets you in
2) A simple padlocakable key safe containing a kley to the switchroom, secured with a DNO padlock, nearby, another copy of the switchroom key is kept by the customer, the switchroom key only opens that door, not the others on site