SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2f573e748e68e48193505f657e04245a19169f9982f47ea9cba6eaef8fc29da' 
  AND token = 'ceZQMG3wwmDrVPjgYliG2g4Q2EZdAveLXtCsithQwtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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