SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd90f2ab18621fd5f7ee426a204edc55e4b3a2ff05afc411b7d808f6616f072ec' 
  AND token = 'OZq59kclqoQ1ohCOIH2bFy+ii17rRVJXyBLizkpQ9e0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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