SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fe48198b917044b37c0017253e8e1c43ee356a2ba51a10fe3dee54562951d61' 
  AND token = '0lmoqW5uuOxNcEBszHwed7MeTCX9jgyWSiKtv/F4OLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}