SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86b68d53592120dcffc0b09d71a2e5de29ba1b63643259cc5ee7ba10f432d2f5' 
  AND token = '+hMEx+kVC7eEgNfJFyGspHgrxVsTQGY6aXHuwVpw/7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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