SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66e032247191285d4db7a5f98e53a13624bb75ed0e78f3cc08f1585114bf0edf' 
  AND token = 'P6KkIjLj8FTAJG8fWj7HbSK5aWboO2WZmaICR3aC6BM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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