SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8dc16f589cf5f4aa52552accdd83028c42069bd561bb745a1814a5a4335fe147' 
  AND token = 'aGQfBNQvDYQcKphCYkOuUQvhyjwBsOJE78a/geD7fPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}