SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '691818da1e69bc019b5c4579fa41c1cbf1828be440b5e55b6ed2d9cb2386927b' 
  AND token = 'bKJMBu3fl/YEDdttxolALcozKxd+4w5bkX9pRWkEBgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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