SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c845eede25ed1768be105ea0872cfb58203b9ca51adb0f8fb876549194da58' 
  AND token = 'Fzn9TqhNsZN7pzAIgO2ItK44YQs4EbtZrLIFXJ09rTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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