SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2595e0a598f2207414fe493c6ee43978610ca26525a49f11439594e78b03e69f' 
  AND token = 'mChHR9+q80gwrOwOgVUjyY8et+vgJmOAI6kIHtpLrGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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