SELECT 
  1 
FROM 
  cscart_ec_print_temp_designs 
WHERE 
  session_id = '7H0A-44PA-IMP2-5L1U-61R7-H6H9-K0F4-W9QS' 
  AND product_id = 184 
  AND expires_at > 1770181217 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00039

JSON explain

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