SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'aedc4951a3de223ae874987c7851bc17ad87f67437e603fd32d5bd22258239f2' 
  AND token = 'o+s3qoTZUITjpVOtXLP6JMZsXBd+rcm0oT2YC653d/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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