Idea of Password 1 Icon
The icon has a skinny rectangle with curved ends which is connected to a circle with a smaller corcle at the center of it. At the bottom left side of the skinny rectangle is a smaller rectangle shape sticking upwards.
This page shows the different variations of the Password 1 from an Icons8 icon pack. Feel free to resize and recolor the icon, and then download the icon in PNG format for free.