SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a70f97a6b8cc48f6d2d024b753ca054f902c9527a2949cfeec07e984e9219701' 
  AND token = 'BY01P09yWdX8sj3sceqAPlw99yTWK2jNtqaoLgxYvtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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