SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73e1f6f42a4c650d73afa56f67eeb9614fc0bf525890a3335bb62d09e6f72fc0' 
  AND token = '2sXhg2qlVZbGiHwSkIZcuoApZeCMUPP9FRaFlCEInhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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