SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '754075c3fb3e8c450fc3b4e41b1e80e8f6f181c590c1bf9ebf5f31f415220a45' 
  AND token = 'TZ8LMlbzhC9+qkiIXfMluAaWs6ksLmj0GhBYA/PMzrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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