SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e5fb3d17ad5aff633d0a2bd3170b27ea915733cea494d36fd703aaa4d45a2cd' 
  AND token = 'X5qVYXoPgOW1lV7CwNkpvk65zeUg9Mj7A3ZhVuZgEEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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