SELECT 
  1 
FROM 
  cscart_ec_print_temp_designs 
WHERE 
  session_id = '0QAG-D1Y2-EM1S-WZYW-5V5S-6KRR-GTQJ-JH8X' 
  AND product_id = 90 
  AND expires_at > 1771080789 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00149

JSON explain

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