SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5705dc313ab67af1f8c5cd04e3ce0694bfb9b36b65ee0958c91a1a924d57b5b' 
  AND token = 'MsavePUXy5CZweKgQdaxRxksOjKlGppw+MdEtXsjTzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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