SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = 'CE05-V91X-5T8R-1J0S-GI7T-M1K3-4D7U-30NY' 
  AND product_id = 128 
  AND expires_at > 1777401111 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00045

JSON explain

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