SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38794e2b1ab2cac638f12ef99051cad5487f518719125264f1272d9c9c402c06' 
  AND token = 'JhIC0wHvxlA939AzsSBxvytN0Y/jVqHURYDbbCB56/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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