Sandbox

SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = '6GCZ-DEVL-FRR5-5X52-TGSJ-9K2S-XSON-DEOQ' 
  AND product_id = 189 
  AND expires_at > 1777906377 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}