SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '206ad7df95fde652ef163e7f25372f578e0b06c39dfc8e976f79d95f491752c1' 
  AND token = '9SZhfKvW0Kl1oAljhEAeE2+Cb4lYyKLrSSKig44mSD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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