SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60df88a218ccd602c71eb47236a7f17d1706e0d07e453cfb4b620da606c101bd' 
  AND token = 'mBb7jEBWDfN4U73QsXOfinI85IUMEmeVF66sHnFAoGs=' 
  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"
    }
  }
}