SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caa6dd9dc61cdbbd01d07f4e62092fed5b6a4bab1f9fcc03e73b803b8145343c' 
  AND token = 'LjwOmXjg5EELTA3ylWLyC3RfbYQWfTZdxw9HRxFlfmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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