SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53efac8aad0ea3bb357b67e5e073627b3454e42babc678c1643fdf2733087de6' 
  AND token = '/FnhmmroDJx+cwBYgQ1G+BjH1JfV3vhvL5vF+nnfnIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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