SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38de59c152aff2579bfb9317bba726e7afb522f289f85f348b04d5ab8cbd9b86' 
  AND token = 'J8+cvzcnpK2bY3QDdsLX5bwrjRvxZzUr24keUbxaGis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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