SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f489f60e6762abbe7fc4df37fd4d8faa61cab51ce7651bea1954069c7fa6f756' 
  AND token = '79qaFPabNUdK364KznIbcJXJF2UxAEhClR+JG8AygXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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