SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c3504b349111a6d9a05729f95e30c64d33ec37d432153fdbd41811f828ca8c2' 
  AND token = 'YphGNB/YcBoznZAhMYipz8pGGyV+HIJKRkGUKtUovd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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