SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4ed86c56cbf8eb560c4096dec6d27ab28a41d433bdbc565d970b2f067a857a9f' 
  AND token = 'W8bab6fAqJjXiGaWUF/p+GhKdWCATPEBb7V8ZahjKw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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