SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ed53cb07ca2232403a9d98dfd19886f57783ae206f8eedc7486cb0732a1a7b3' 
  AND token = 'NqfOoGKUBYIoTFQbJ0K+oyNmbXxL0k29GbUSFmXLohc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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