Searching for the product by name is the exact same UI/UX at the self checkout and it becomes an exercise in frustration IMHO. The typical staples quickly come up but for apples for example there's such variety that you're often paging through a page or two. Meanwhile, the human powered checkout the operator usually just knows the 4 digit code and away they go.

As someone who's worked at a grocery store - the 4-digit code is also printed on those little produce stickers, and will generally also be on the labels with the prices on the shelves. Use this to avoid searching by name!