SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e657a046702249690b2eeb209185d15eadd500e5279ce6afcfd888ab0ad7011d' 
  AND token = 'DsmtWGO16kTs+Wyni2eDJdfhjvJUU8UOCVmUA8IHtQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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