SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5428f1e739a968bd3c992f3e02e04a499d4782522f446c6a64cab0209e692a91' 
  AND token = 'N6AIYZGE0YMAkFtwf8B7eKZjvHLYxzK6MvHc0MHFav8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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