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 = 1 
  AND cscart_ult_language_values.lang_code = lang.lang_code 
WHERE 
  lang.lang_code = 'en' 
  AND lang.name IN (
    'text_gift_cert_amount_alert', 'recipients_name', 
    'purchasers_name', 'amount', 'gift_comment', 
    'text_no_products_defined', 'gift_add_products', 
    'how_to_send', 'send_via_email', 
    'send_via_postal_mail', 'gift_certificates.recipient_email', 
    'template', 'address', 'city', 'country', 
    'select_country', 'state', 'select_state', 
    'zip_postal_code', 'preview', 'purchase_gift_certificate', 
    'gift_certificate', 'text_gift_cert_amount_alert', 
    'recipients_name', 'purchasers_name', 
    'amount', 'gift_comment', 'text_no_products_defined', 
    'gift_add_products', 'how_to_send', 
    'send_via_email', 'send_via_postal_mail', 
    'gift_certificates.recipient_email', 
    'template', 'address', 'city', 'country', 
    'select_country', 'state', 'select_state', 
    'zip_postal_code', 'preview', 'purchase_gift_certificate', 
    'gift_certificate'
  )

Query time 0.00141

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "52.81"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_ult_language_values",
          "access_type": "system",
          "possible_keys": [
            "PRIMARY"
          ],
          "rows_examined_per_scan": 0,
          "rows_produced_per_join": 1,
          "filtered": "0.00",
          "const_row_not_found": true,
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.20",
            "prefix_cost": "0.00",
            "data_read_per_join": "408"
          },
          "used_columns": [
            "lang_code",
            "name",
            "value",
            "company_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "lang",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "lang_code",
            "name"
          ],
          "key_length": "392",
          "rows_examined_per_scan": 22,
          "rows_produced_per_join": 22,
          "filtered": "100.00",
          "index_condition": "((`atulecarter_atul_demo5`.`lang`.`lang_code` = 'en') and (`atulecarter_atul_demo5`.`lang`.`name` in ('text_gift_cert_amount_alert','recipients_name','purchasers_name','amount','gift_comment','text_no_products_defined','gift_add_products','how_to_send','send_via_email','send_via_postal_mail','gift_certificates.recipient_email','template','address','city','country','select_country','state','select_state','zip_postal_code','preview','purchase_gift_certificate','gift_certificate','text_gift_cert_amount_alert','recipients_name','purchasers_name','amount','gift_comment','text_no_products_defined','gift_add_products','how_to_send','send_via_email','send_via_postal_mail','gift_certificates.recipient_email','template','address','city','country','select_country','state','select_state','zip_postal_code','preview','purchase_gift_certificate','gift_certificate')))",
          "cost_info": {
            "read_cost": "48.41",
            "eval_cost": "4.40",
            "prefix_cost": "52.81",
            "data_read_per_join": "8K"
          },
          "used_columns": [
            "lang_code",
            "name",
            "value"
          ]
        }
      }
    ]
  }
}