SELECT 
  1 
FROM 
  cscart_june_setupec_print_temp_designs 
WHERE 
  session_id = 'V0DO-M1G4-DKAQ-ZJ5D-T5NP-YX7L-4BP3-H85T' 
  AND product_id = 71 
  AND expires_at > 1781894641 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00019

JSON explain

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