SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4167fbec4824d2b8bf604c63d6850fe6140ffcd67795e7aff1d396f212b2b394' 
  AND token = 'PtRdqg2ZKmeVuzuUxVg2E3gDgUoJmT3wTcSFU8iGtXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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