SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f4b462d5c403a8e8e64501a0ed02fcb2f01e890fd03e1a67b184741e1742a68' 
  AND token = 'Sd2o41GNnKFcxDw0A9ZMU7xgnp1ABybDTAyTcP7EhWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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