The occasional misting isn't likely to be of much benefit, as the boost in humidity is so transient. Wetting the leaves is of no value, either.
When I have run into those situations, I inverted a clear plastic bag over the plant and pot, leaving it open at the bottom, sometime using a bent wire frame to suspend it, so it won't make contact with the plant.
I recommend you invest $20 in a seedling heat mat to set the plant on.
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