SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9e6d911f96dd51a8a101b7e8244db4a3ce5fa9e6d27f774e2283c1646a1cc8f' 
  AND token = 'NwBK6NSDpKaEwDmOYGUTvT70Y304zhOmzihqYH3PgPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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