SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf21d6086cef625fa897bcbfb7210c3ed913c409f36fb0c54c280e6e910ae177' 
  AND token = 'O6hsnV33DwvomFRNsYgFu+YkOTlBKYqoi6XUJX3oDMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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