SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25217452e5a1531274c2c784241165de0304cdb098ba21b7283ae48c94864539' 
  AND token = 'hC1HAIllWogyPxZ9rxanwlfgfjUpkgiM5YJzNYGy7K8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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