SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1bca3e894bee9eeb9715f24ef8d2d4e451bc024101bc4edfa0ac7d12b8f2925' 
  AND token = '+otxxPRqSFhOz+7lPaAoytOUhIwxn5GlhKIrPvqrY/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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