SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ba36af661c886afc00f9841a2c0ca5c63c7720de1776774a972c5c00c6ddc25' 
  AND token = 'bczz5H1IBBRjzhmt7r9YUgeBTM2q+eu3uDoHWP35DHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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