SELECT 
  * 
FROM 
  cscart_profile_fields 
WHERE 
  profile_type = 'S'

Query time 0.00054

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_profile_fields",
          "access_type": "ALL",
          "rows": 45,
          "filtered": 100,
          "attached_condition": "cscart_profile_fields.profile_type = 'S'"
        }
      }
    ]
  }
}