SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6881eecd4619d8752b18c37ab0ee054f5830d70efa4dfaf138d750bc28fa5c26' 
  AND token = 'h/w/TuZUUmz76tnZK1p9Vzp+XBLXrFrq98Gk4BpzPJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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