SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69e7bf0588402cdf9cb91a80c75a1fa819487935787a958999e37d56014f1228' 
  AND token = 'D/AIJv0PnkwA9GwJqK1fdf3jOt9cxG4beJhRCMFRs88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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