SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dadfe032ebc7bf7d24615b79757468f3c43a9281fc7794666c0d039962f60cbd' 
  AND token = 'JSgZ8ADkH47a44vlxocY6GAyhwUhIIkruKhjUHjHPB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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