SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b364e6ded79c5a3903d0929d95f4602830f36c779767e9bfb0fdf0fab9402038' 
  AND token = 'y2nWWPDyP8VpZP13OvOHYrpMSqmurXCuzKZzfWQ9LWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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