SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a89d7d33bd1982108d5e2524719da125515e0caaf9e03330eb97fe9061dbe8e7' 
  AND token = 'AuzJnp0MskcB+4SYTQ0DG+qg23ugG/kCAE/GbLoz8zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}