Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec2fce43cc68cca612f54e1771f7b4c9db3e2d3f0cc3de7e896ee98e4a12431f' 
  AND token = 'd3QqpTHiIoP1RvEkvahAtKQRjU+AAs0Un4KSK3HiRDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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