SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb5606f41d77a7c9253156ed2c4b5b3af544d3bf29bf33b4ea0dce56a6e8de56' 
  AND token = '0LV5Nk97oi47AgjVZiKzLUTSdiqQeJjKf5d6I0l/ZpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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