SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a7a639bdcf28f09a2851ab364e21b4d0ad0ee64345d851928802b7bf41a4e82' 
  AND token = '22RhQ0LEuxeOjc2UTrIApb04EmZQ5hMaoSdKFw1BRSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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