SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5c6dd2cac87e2489afd6e789aebb397d061010a81a32fd02f9756efd0d1a341' 
  AND token = 'WBBKQgUGmtTMuzUeIROzDJAgdieyiDkN1Ab8h0jkgZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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