That crack isn't bad at all, especially if it's following a mortar line. Are there doors/windows nearby, or is it close to a corner? Insurance will almost certainly tell you it's nothing. My area had a quake a few years ago and I got a bigger crack (maybe 1/4") above the basement walkout door, also through the mortar like this one. If you wanna seal the crack then you'd have better luck with caulk, mortar would have a hard time taking to such a small crack; and sealing it would make the area more difficult to monitor. Just keep an eye on it over time and bone up on the water management around your house to make sure it's all flowing away from your foundation, not loitering. I really don't think you've got something to worry about right now based on what I see, and I've worked on or evaluated hundreds of houses. Rest easy, friend