SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7edd518403e829192cd9514bc69bbaf8a336f25e98517e403287cbf8bd637c20' 
  AND token = 'X3W4MHBgbDng7qo3Rtq3VQURblAaUKcFHTyEIf1Y7DU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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