SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = '4YYU-MEGW-1YJL-OQ12-G5O6-9MQ5-ET3X-Y5OC' 
  AND product_id = 192 
  AND expires_at > 1777130736 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00039

JSON explain

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