SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b30e50da3fe51892138877c7d5963fd892c4aef200b702ed0cdfa7fa1243b89' 
  AND token = 'ABXBlfvMZm1q2TQfpxEUY6VkD84AyQc41KHC6NfDkwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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