SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b82a835ca98a1c55de427055a4a50d652da8a4c66df1441965589fff7b96fd7d' 
  AND token = 'mq8xDThDvnok6MW7K+i5q22GEhGhkKT2G9PYLS6NyPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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