SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa2e11acf7ab0afe53d429293baf1d5dde3033e1e95606207269d82086b3862f' 
  AND token = 'LJQiTbIzMu9oE6tzeFoNhEsQqbtBwvCBZTxZ7OvNfyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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