SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '778a19421866f2f257745fb28644e8fd368c8ca4204215a3bf5677d9c4a8adba' 
  AND token = 'HqfGK54bVVbSQpE5gVwQ2X30EzQnrnhI8EW8YB+yDNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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