SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5742a20de036f9184856ffea27baccef4f843c53349b91c4dc5964ea909ff4c7' 
  AND token = 'lGxgjmz03JIOAOgqYHc7YtEPfN9nnVf6Mw6pYDjh87w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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