SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c063b6e5a945ef2299a9cb331bc572c49f6ef968b68828574b4e793a5922ceca' 
  AND token = 'CDyfRAuJpjjhL7bvO5X34m723rBmyqU+n1+eVzdPgEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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