SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acdeb9ccfbbf802199b28528e1f9775aa0be99085f6bea8c84693907451d1742' 
  AND token = 'hRVJf/avYlbBkmbFn3XxlTNcCQzTp7YKdEI22vTp6O8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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