SELECT 
  1 
FROM 
  cscart_ec_print_temp_designs 
WHERE 
  session_id = '6O4J-B939-MU8E-OEG6-A5FT-B96H-EUDY-BVTW' 
  AND product_id = 190 
  AND expires_at > 1770181196 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00038

JSON explain

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