SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = 'NT4S-TL5E-E2M9-I1ET-0H6F-QAQY-C5UU-OUPO' 
  AND product_id = 108 
  AND expires_at > 1777118183 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00044

JSON explain

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