SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83112809f5d6e6e2761a787a476fa1bca6d7432babb9acaaac960fb4bdb634c3' 
  AND token = 'oOkTiYoIO1PvKSS02lUZzcbqurvdTZM63AilUCvf+JA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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