SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e783cf1ebe8c3f81cb1ae8a89a0c472a9bc9a81824b2f734764a3e2575cd16be' 
  AND token = 'QtWbUuQ7iYyy5XkLuM0QrCidWxnSrK9Urbb53mrEJBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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