SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09644b36ea7c35c15322724852830ba1d13b3564e668c5db17b24c9291981a92' 
  AND token = 'dOflgyBqLvCgWNKifKVEJVaYTue37aY/i6PaZ7gs9Bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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