SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce51812ddbca8351627911b45c8bc490f573883f6dbd60643b97e7f2401c9642' 
  AND token = 'ukJimLKlAj+WyUMSsWSlBq48eLLyld1xwgj+tlFDHes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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