SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b663cd25dc69b9aa64c82dd9f484c582442ff111d13da400ac18c3d6be879db' 
  AND token = 'OM5A8/wPfvKUgl9Ky+HoKKlUBZwlq++tRzK7rBtAuQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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