SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '029d5a152af668b87e301315c10f37cbdc3a6165a3585e81508c59156057a4a3' 
  AND token = 'uQXLzu5MyVlDuprENGvTOEJSu4aKher0ncfpRbV6TzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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