SELECT 
  lang.name, 
  IF(
    cscart_ult_language_values.value IS NULL, 
    lang.value, cscart_ult_language_values.value
  ) as value 
FROM 
  cscart_language_values lang 
  LEFT JOIN cscart_ult_language_values ON cscart_ult_language_values.name = lang.name 
  AND company_id = 2 
  AND cscart_ult_language_values.lang_code = lang.lang_code 
WHERE 
  lang.lang_code = 'en' 
  AND lang.name IN (
    'cannot_buy', 'no_products_selected', 
    'error_no_items_selected', 'delete_confirmation', 
    'text_out_of_stock', 'items', 'text_required_group_product', 
    'save', 'close', 'notice', 'warning', 
    'error', 'empty', 'text_are_you_sure_to_proceed', 
    'text_invalid_url', 'error_validator_email', 
    'error_validator_phone', 'error_validator_integer', 
    'error_validator_multiple', 'error_validator_password', 
    'error_validator_required', 'error_validator_zipcode', 
    'error_validator_message', 'text_page_loading', 
    'error_ajax', 'text_changes_not_saved', 
    'text_data_changed', 'placing_order', 
    'file_browser', 'browse', 'more', 
    'text_no_products_found', 'cookie_is_disabled', 
    'cannot_buy', 'no_products_selected', 
    'error_no_items_selected', 'delete_confirmation', 
    'text_out_of_stock', 'items', 'text_required_group_product', 
    'save', 'close', 'notice', 'warning', 
    'error', 'empty', 'text_are_you_sure_to_proceed', 
    'text_invalid_url', 'error_validator_email', 
    'error_validator_phone', 'error_validator_integer', 
    'error_validator_multiple', 'error_validator_password', 
    'error_validator_required', 'error_validator_zipcode', 
    'error_validator_message', 'text_page_loading', 
    'error_ajax', 'text_changes_not_saved', 
    'text_data_changed', 'placing_order', 
    'file_browser', 'browse', 'more', 
    'text_no_products_found', 'cookie_is_disabled'
  )

Query time 0.00114

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE lang range PRIMARY PRIMARY 392 33 Using index condition
1 SIMPLE cscart_ult_language_values eq_ref PRIMARY PRIMARY 396 mahm3t_cs443.lang.lang_code,mahm3t_cs443.lang.name,const 1

Result

name value
browse Browse...
cannot_buy You cannot buy the product with these option variants
close Close
cookie_is_disabled For a complete shopping experience, please <a href="http://www.wikihow.com/Enable-Cookies-in-Your-Internet-Web-Browser" target="_blank">set your browser to accept cookies</a>
delete_confirmation Are you sure you want to delete the selected items?
empty Empty
error Error
error_ajax Oops, something went wrong ([error]). Please try again.
error_no_items_selected No items selected! At least one check box must be selected to perform this action.
error_validator_email The email address in the <b>[field]</b> field is invalid.
error_validator_integer The value of the <b>[field]</b> field is invalid. It should be integer.
error_validator_message The value of the <b>[field]</b> field is invalid.
error_validator_multiple The <b>[field]</b> field does not contain the selected options.
error_validator_password The passwords in the <b>[field2]</b> and <b>[field1]</b> fields do not match.
error_validator_phone The phone number in the <b>[field]</b> field is invalid. The correct format is +46123456789
error_validator_required The <b>[field]</b> field is mandatory.
error_validator_zipcode The ZIP / Postal code in the <b>[field]</b> field is incorrect. The correct format is [extra].
file_browser File browser
items item(s)
more More
notice Notice
no_products_selected No products selected
placing_order Placing the order
save Save
text_are_you_sure_to_proceed Are you sure you want to proceed?
text_changes_not_saved Your changes have not been saved.
text_data_changed Your changes have not been saved. Press OK to continue, or Cancel to stay on the current page.
text_invalid_url You have entered an invalid URL
text_no_products_found No products found
text_out_of_stock Out-of-stock
text_page_loading Loading... Your request is being processed, please wait.
text_required_group_product Please select a product for the required group [group_name]
warning Warning