SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '640781d12cf4960c9f7ab988cd369f84c255fddbcae2f848a1633b9a6f5dc3d6' 
  AND token = 'hBjiaPYWbrVwqEmG3IQU/gu2y7iPzroeTDd9tW0Em0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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