SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = 'G1BN-F016-QFGK-2V1L-A8W8-IUHO-2XEQ-AW2E' 
  AND product_id = 143 
  AND expires_at > 1777124071 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00032

JSON explain

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