SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = '32SO-7514-7C7Z-RRUJ-D1AJ-V6V8-28CS-UM25' 
  AND product_id = 72 
  AND expires_at > 1778412847 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00037

JSON explain

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