SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '806557894e0464fe2ed0eaa415fd03f8b7f52e71a7fe54afa8103a277b3240c0' 
  AND token = 'JVh6Tgz+xeTyrOagB5nSL7o9AqiqjUKQAb5zNeI8KcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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