SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4f945ffcdb8e62a2a7369ea73f2443d7d1375be851b6ff534298e807dd93053' 
  AND token = 'N4PzGkjiU++Mk1jJPFJmRUulHB6pAp70zbGaQT1ATKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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