SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2986b5e1dac935579100960126fd6e335d89b5f2253fc11bdc1a9eae4c859766' 
  AND token = 'cmwqgsXtU57TSmhTw3z2hD+MUCzd1Kv376O+Ntu5gkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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