SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '393811cb0ed13c12f3b9b3fd758bd82f2fd51a635dbe2d4afbc682475b88ee9c' 
  AND token = 'wXJ38cBEh/brwufLKW+RdRANj7CR88xA0VwPi12WM8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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