SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '718cbf52215bf7f4a7019a30165e90348e51fa2757a7c80b564a98614a18df88' 
  AND token = 'VWWa3ZboF5zdWO/Q9rKlYNqYRR6zf+zAQFUx7TfRjBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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