SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79e82edbf68779bee38897b37711ad168c497ff86387af164674fa6cf9b8350d' 
  AND token = 'zeDkGdFd3sdMlnhHmwZbZNPKK+V87l59+o35Pmn47aE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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