SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b54a1b01f005ec9d96223e7bff0dc8e74b09d0cb3f369db1d04842b8ec29ccc' 
  AND token = '+NU23mygQutUlxKOA/X2XRKTsKcYtfyAVk4Xo9WgXDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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