SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be84e6adb86c532dac652f2ef191bd2be9e5fdb1bbbe076fbae2d15b59a6064a' 
  AND token = 'vf6GEDsXD1BKyy7o1b6qBP3U/mbi165G6KsShp0gDZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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