SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '20b9c7694d3374caef984cc8e9c9dffd1b8e131a20ba74033b31a3c8fb68601c' 
  AND token = 'r+GCnaISxhl5SjJH7OXQOBP+JsKPL3yTOhkAumUXHVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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