SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f25d996cd38da47bff5d54d532445ccccf2ecd0bd4fa73e608d711b14354856' 
  AND token = 'THFv0M0kzt6EfRTZlzRSlGmM2WqjhDe5N6HcgDQHScg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}