SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd23e1745219e9754024d32a6aac628c4af7ac43117547b6db6efd9c380bff70e' 
  AND token = 'fgsA8ndavQAABax1QeJHUPxI2CNA4r1CBfEpbtodRFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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