SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddec0a8ee5448171d538499eff52f62c03c57949b44a6b2d48cc1563cd2f5613' 
  AND token = 'vD+c7hIJuiBp93XNUJjuz5EjxLQcfi5/VAcBTWwhf8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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