SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db92440a7712055943b32251ca91032c1ade20a89deb2b90c6ed7e33b3ae7f09' 
  AND token = 'uNoNg6oVtTC24RE/OtwLeqqDHZNHQlje8Lu3xLFgh9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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