SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e609183cae1c31186813a18e81db322eee55a79a4a0960d201d7f96d9eb8ebe' 
  AND token = 'LFgRGFcpw2K4xF3uKTzrnLniHQgcuIBS9saS2Wq0fY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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