SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09ef7f164309c6cd40fdf8e97fa7c18caebfe7520fd7e195e5904c842be943cd' 
  AND token = 'mDh19hV2nyJdu9zIHPYnrxtaf6BmdzIPFTgtbKL1WBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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