SELECT 
  category_id 
FROM 
  cscart_category_descriptions 
WHERE 
  category = 'Gallery Products'

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_category_descriptions",
      "access_type": "ALL",
      "rows": 415,
      "filtered": 100,
      "attached_condition": "cscart_category_descriptions.category = 'Gallery Products'"
    }
  }
}

Result