SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd86769b17b6005474854948d848f8df6b040bf66fee99b035d5fa174a457f42' 
  AND token = 'voDUMJGQNygT4y5wZlfqwyZQsL6XAXGktkScosXtcwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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