SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53b367efdbe9e7ad65803ce9360072d1f3d4a19cbc8989b9b9655d871498133a' 
  AND token = 'Du8ryqIECoNvvlVQ2EQSe0qqW+ncfzE2ei0I7IKeAyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}