SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c5c4ffddb23d5d6ff31526f6243f3c93285cf7e2352543c51d339f1e5887f02' 
  AND token = 'Usb9H3EPEVVboBAxj5k5TeWnXlWxdA2VyIIwJOmliog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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