Odblokować 2 and other 84,100 icons from Icons8 icon pack follow the visual guidelines of the operating systems: Windows, iOS, Android KitKat, and Material. PNG format is free up to 100x100 px. Icons are availble for download in PNG and vector (SVG, PDF, EPS, and more).
It's an icon of a lock. There is a circle to represent the lock mechanism, with a small black circle with a rectangle extending from the bottom to represent the keyhole. A curved line extends from the top left of the large circle, and arches almost all the way to the right, to represent an open lock.