SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3638a439d3910173e3637bd716bdc5cb2cf6cd3257958f98821e9c0ab9e41103' 
  AND token = 'NhI49Q/gQx8Z2SJbWj6ukno8v3XqRykZu9M+3eooLYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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