SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c74278977c541f8887240b5635925da3cef3d306138c6817ccf2a28418cb12f' 
  AND token = 'sL4xJhtt7O7N17gtekO46EWNUZBiFBMCOGBAjEaII0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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