SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44f1a3c38c5b08a99d1212da4a993ce3cac45408e9a7923b302256458401b9bb' 
  AND token = 'BpzeCMZCFJKoZipcUXK+/f7ird7Fk03TBSdsgKQjQUs=' 
  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"
    }
  }
}