SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c37fc2b610ed7b0eb63376d0f0e379a743eb164d38cfba45d6ed81ef971cded' 
  AND token = 'Y2P5MNLfmnFCqSLKRMYOzzl0JMcs1XpXNavRrH1EgXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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