SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91c5711c6c47989327db99aabdcc8ccbc040097dfe2b30ccdc89bc7cc88ad268' 
  AND token = 'C44pTHlrHubML0v6cx+88P6YFRWbZw5158Bla87pMHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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