SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3144c0f76680867e829e52003b1fbe303f9aef0109dc58cb3946f0151cd89c21' 
  AND token = 'l4zI1kZdMasMJfoO5vXT/w0+oWDEu4/y2BUq4G0FNEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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