SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5ec8fe8b8094cc3bde28012429ba4cdf4efd5ae93068bf8c0c6aaf049453103' 
  AND token = 'PwemjshCoSgvGZwsX6QV9dcpDjTPPODVh8MO6z3capk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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