SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '591268c8eee7338c66f64084907a385ac4f702ef50414ea58cfe7df7bf1d772c' 
  AND token = '3C1/QFVVgZ13PHyfyI+C0OPh0ftlBqg2zv+3do15HOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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