Cracks, even small ones, can be an indication that there are serious problems lurking on the other side of the basement/foundation walls (the outside, the part of the wall that's buried in the dirt around your home).
Pressure on exerted on those walls from the outside from soil expansion (when it rains or snows, the ground gets soaked. If it doesn't drain properly, the soil will swell, putting more pressure on the outer wall of your home's foundation).
This is when small cracks develop on the outside, allowing water to seep in. As the cracks grow, more water enters and it weakens the cinder block, concrete or stone that makes up your foundation.
Soon, the inside walls will show cracks.
When you see these, yo0u'll start to see moisture, water, dampness and possibly mold. All of which are symptoms that the basement has a huge problem.
If this is the cause, an epoxy seal will do almost nothing, especially long term as the cracks grow and begin to separate.
Ask your contractor if they use a steel plate in addition to any sealants. This will help keep the walls from coming apart further. And, they have to address the problem of water in the walls and the pressure from the outside.
For more info on this, check out this link :