SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c488e5f987139fe332caffe2da3bb68d9886600aebaf7dcaf8f47d39fc9bc33' 
  AND token = 'x5WzhzEOwwXUsM6GaBDQacbbdB+D0hq4On7H8NqeZHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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