SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf8bda26c1e4e3ab209244545703c2ed2e1b9bac716fef483461c0638688b992' 
  AND token = 'HRQ8Xpx/NnsuBgX81c3xJQTI51zcbK2mAAkHl3+MoK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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