SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '344a4ab70f7a23ec47c30421952792ed2f672040fbb8e9dbb3e6079f7d353029' 
  AND token = 'DADHpioQ/vXG3zS/uH1lglkZ2f8NhppHw3cS6w+z6xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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