SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d1731fadf1cba57f7e87fee7fca6f8211bba4ff439311c946a30fd2d6e30a4a' 
  AND token = 'Mio8OZz+rFl8Spo0+rq0QFO7whP3dgI0DWSJ6gInTWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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