SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a32a450fe0ac34fcf7fd88490f72a9e51b16a10eb5387fe9b4be65f78eb3762' 
  AND token = 'HcUZ94HyuPQxTFiixFSAJZH5cqzttWxCtd76FemdhUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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