SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd599e2fc942f6299068f7993a215ab7309f3a9f7acbc856ac7f973db94109c9' 
  AND token = 'n38SLIjIbB4IVgiU14aiuebNWhtnNqYdhN5P4eHX9sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}