SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7df83fb31a76aad3963cbfefdc72948957c006c5139cf13ada8d79ac1dcdb5f' 
  AND token = 'ErGRz4qZ2+7OUO8q5Tzzf/PLsFjzmX3psuMFjhKKyOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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