SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad99bec7e8af9394eba8b99f46fc17b9323374fea41a8794fd4a9b3750fc3e5a' 
  AND token = '/wOiswKWltAtK88RmHiTk7d6OwwMMdWu0RqQYO1bzeI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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