SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25bbf2887085e2d0baacf5d4f390825428a65cc71cf544be5ec05f731d7fb280' 
  AND token = 'k7h2DEnojUUNKYrXMIS1jKzYqKD484bm8RZgvwaUOGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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