SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bcbc79fa9e07f5d4ecd4ce9c2e8799f2742e2eaffee232f648c9964bc07477e' 
  AND token = '/Kdvza4u6w5rzdLCUdEhZtTlA8JmPDyYr9WbFFbZQYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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