Fruit! I eat plenty of veggies, but I would be lying if I said I had them as a snack very often... fruit does the trick! It's easy to grab, requires no prep, and it travels well... Don't listen to the silliness about fruit having too much sugar... it's way better for you than most other snacks.

Veggie or fruit with a nut better(almond, cashew)

Here is a video with healthy snack ideas:
https://grokker.com/cooking/video/habits-eat-small-healthy-snacks-often-day-11/631a25a990d9eb01d4772621
It is part of the program https://grokker.com/cooking/low-sugar/program/30-day-eat-less-sugar-challenge/62fea743ec4131206e92f356 which may also be of interest to you.