SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4473926ac35336cea501d197eae8253ba256e5a541328e1b230c7ad2fbf9da17' 
  AND token = 'CGSJqZywSb4nKHXggoQWkJ1msVPnPoL5dNHBw4dGY8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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