SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4863cae85d1b79d14df0d01f8d89e92e977b23b5ac7cca0402ce53f083a95794' 
  AND token = 'SMZ4Z+SmQB3FZxF2N0KaRga8sIDLlMXJTM+2bq09aLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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