Sandbox

SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = '0S50-E5BK-6MEB-NFJF-SW1K-4QQO-E00F-RVBB' 
  AND product_id = 16 
  AND expires_at > 1778209921 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00043

JSON explain

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