Try adding explicitWait.
WebDriverWait wait = new WebDriverWait(driver,1000);
wait.unitl(ExpectedCondition.elementToBeClickable(By.id("lst-ib")));
driver.findElement(By.id("lst-ib")).sendKeys("Selenium");
driver.findElement(By.name("btnK")).click();
Try webdriver wait and let me know.
If above does not work, you can even try using name.
WebDriverWait wait = new WebDriverWait(driver,1000);
wait.unitl(ExpectedCondition.elementToBeClickable(By.name("q")));
driver.findElement(By.name("q")).sendKeys("Selenium");
driver.findElement(By.name("btnK")).click();
Hope that helps!