SELECT 
  style_id 
FROM 
  cscart_vendor_styles 
WHERE 
  company_id = 2 
  AND layout_id = 6

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}