SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47ad2f143a9d9ff609d3102249b12c3724ed2e0185ad126ebf047130f75ca79b' 
  AND token = 'uNhm90T/hzMesmloY/wgP1lDQ/VKcSODGIeL5VYxjFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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