SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99654bdebadc1b0524152598586c36b25938fc1b5053c060463d8d02b9e1a34e' 
  AND token = 'RFSAG5FY73hp4hGgIe3v7Gpzu3lsfVgsUh0KuTFq46Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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