SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '434e427bb9955bca7cd88cf94a4e1898e9c2f14ff2c6024df4590c7f5747bbd8' 
  AND token = 'uQ+Ywrz2twh7N6D65RRd/zxknQAIuwcbKGCxDjKQgp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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