SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7326b9950d8067560858c46c7e3be7a5907f7d2366c2abaab43e914d18331ea0' 
  AND token = '5EF3Ju/zk3IHRvNhCjXy9BYkOxTum4P2eMKo8iZ/Wg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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