SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '411fcb77eff2606ba4e14377ecd767113d0df687f0e5b337c6ba84a7bbf84021' 
  AND token = '8M1PpqxlPhaALRc6QXl1KkeHcy8KDAHrPdqbwQ4svgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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