SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = 'X8MW-S0X9-N67R-53AF-3DRT-J1O7-3HDZ-5L88' 
  AND product_id = 65 
  AND expires_at > 1777322357 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00057

JSON explain

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