SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14baa7e14de0cd318faa69cd33773833fa664dc87c436b207a77f4bada8a8d59' 
  AND token = 'KsXUVx880MXHBP1fkUEeLKVunJsJo5mxKtUMoK27DVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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