SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f794a0c4ddf1b60979b149407049c5164458dd7606e318b443477df71d9f13c' 
  AND token = 'ERCzX55uWB33o7VkA4hPzU58WfBVYWg5ug9ihaO30JY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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