SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42e8ba8211a52fed7e12e9d0d0470aeb991fc7b137f6bdd22762d23c68a77ec2' 
  AND token = '10LruDho0gZoUXijCEYyW843oRhuD7iFWgIJgF6fGgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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