SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24fd231d2bc94aa537edc820d47352e738baa1388ed32dda64366c873182fc54' 
  AND token = 'qqlZWV8M5xZObHlbCeVkWch9QfXeff+YVLbPvgTQDzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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