SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d35d0a5e5a32976e47299cbd2959627c98a250ab9fe94371b4fcd783e03ec9e' 
  AND token = 'fMJxlgytAFmwn0hAYnDN1OWnGaHlNfqTc0MQdZXtwrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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