SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50deaf8aecac62af36448d8dce559e97671421163361d6868d6a19b873bdf1c8' 
  AND token = 'O2KOvWBxUUvZ8fuHo+ehOIeNXMnUsRVtLTXRFKkWFbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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