SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '832f36612022cfe090672109c350abcd08f5c3e5b592b890c608876379519eff' 
  AND token = 'O+MQ14eQ4eZUeaS7EXooiJdqICf2gphjApxNXUp0jJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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