SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62415a8e9bf46d5f9dd5b014058d8a71a19f568fd11a2acde0c7a7762cc4b358' 
  AND token = 'Julg1kUkZU7PnW+tKJjCK4wvAECL+oFX9qBiJqwyi1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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