SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e79e06857b9dd9161fa339caae0da93fc5bf16712275b38565f9676a8d43dc9d' 
  AND token = 'a8NDUZozF6dlzAkmZ/yTisV3C4wNz+WIaquzPDzZ6Xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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