SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57812477e1ef0ca5e9235f7966226bedf4beb70580725bd3fd369ef3575a299c' 
  AND token = 'nflczQcW1DRxwLZM+BaMBRXlvumEtcrK6qKLBgWjdrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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