I want my heart to get down to 40 at night. My lowest so far this year is 55. The only time your heart ever rests is at night.thats too long.
My HR drops very low. Ive seen it in the 40s. Normals are 60s in the daytime 50s at night. So I dont think thats a big worry but you could phone your dr and ask.
A low HR is good for healthy people. Can you imagine working 24/ 7? That’s what our hearts do.