SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd997e33a557544fd5318c02c3f291077957bdaa7235164c0fbfb5a05b1b38dff' 
  AND token = 'qp8RVuQGh9yHETUOg50fvZYYe7vDjmBVSI4eZDtatGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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