SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7caff3af21ab513d70083a9f588143432719c12a7809900d91e5331814f8b5f' 
  AND token = 'Hv3duqOQoTctvnKjyVFk7w+VdxWBqb5hg8Gg5V7sH4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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