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 (
    'quick_product_viewer', 'previous', 
    'products_found', 'products_found', 
    'next', 'no_items', 'quick_product_viewer', 
    'previous', 'products_found', 'products_found', 
    'next', 'no_items'
  )

Query time 0.00040

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE lang range PRIMARY PRIMARY 392 5 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
next Next
no_items No items defined
previous Previous
products_found Products found
quick_product_viewer Quick product viewer