SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '805631ab356bc1c79acdbf67c99a9e98454071b4e2b46f0262906342f645384c' 
  AND token = 'vGwYqXBowQdYSI3IBx5OyfLNHkLJxoo/eqzfaOn9Dac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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