SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '392d9c180b3cf624662893e72e15c8f8ff09d6a69138009324df9d4594ec79a1' 
  AND token = 'pH3xrz0TroPqarJClbZHWA/JHf3gxKdI38QbyP9H/ho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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