SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '16fd5578e89dc5830b63f251384767ec85f2fc91758b34cb97b1a9e87a23cd29' 
  AND token = 'KFkmho7rGnl9GUDJV2dbYbHIy0QjH3VMO6x1vbPlK/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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