SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a8e21ec02ec9c4b76509e5e1578f5385998bc7b1b7ab394835bf4d6914da744' 
  AND token = 'EWkMZaY7LGHYcjjK8Z7oVh6Ei/6n6WpUQowgth7YtmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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