SELECT 
  1 
FROM 
  cscart_ec_print_temp_designs 
WHERE 
  session_id = '8HUN-4O0T-4Q8K-ESZU-6GGP-EYO4-5PNJ-ITAN' 
  AND product_id = 62 
  AND expires_at > 1770191359 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00037

JSON explain

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