SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '230ff329d401e84cf0ee74e5c74a1147e46138f2b4560b7f46938fdbfc21d4a8' 
  AND token = 'Y97vDAxxASplVDvjgSZR3TJcBfKu3+GrcHoEuB/iPWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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