SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ae6781a8733dd5462c1b8eae2a531ed71f0cf9adcbafe015d07c6f3fa6cada9' 
  AND token = '7WUS4oP5B/U8/YTatmSoQz9JlxlG3IbM+6+G5jNEEXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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