SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0b03910aef2a64dd6100e364921fac474942d0624c6e23c5728539d3bc76f9e1' 
  AND token = 'liw9MtlEcdkU6Ux5GdCuwNh2oEcsebMjGWUPF2IRBQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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