SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '097039cfaecf598f7cd142ed3b28673251257893d84fb503913765ab9db900c1' 
  AND token = 'TsrqKGQRHqLZGFhdBUxbsr9Km3mhc2CKoHqyyH84WDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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