SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '45d6c37033440f315baafd27d7df1e55595ba41450fb22d18b6a11d273fc0bac' 
  AND token = 'dhKWQCQPoOG15QGGZQoiNevWuAB/7iSJRSduowWxP6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}