SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1ad578be8ca4585cdc7a0fa4c3a6b9e0f0f7ac05198a02e2356fb6db4c0f6abe' 
  AND token = 'jM5K9BUq2PIQfgreDLNCfEoZ/xFsWRlivTMeYnwQzcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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