SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce91ed644028c18fc5ebeeb7c834915cd0fc28521f22a4713c70d4403ecbc17d' 
  AND token = 'JQoV8Z1gnOlNGdKtKsoEG7wBKg8B+uBqeWPXOgsFvVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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