SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '015910142968c5a2cd05568313f0d031bca2d09ef835cdc1cae4e9b6d0741ea8' 
  AND token = 'LYu9GolHRVdFan722EHyC+eM7tIZfXjV7aYicUq/FF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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