SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = 'I3WQ-3XX3-0Q47-OL3C-1U54-HFO1-PYBV-U02S' 
  AND product_id = 46 
  AND expires_at > 1777986694 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00039

JSON explain

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