SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '063aeabe4cdee629f851e37ce803d9668b8316dd99a22d623ff5cfd89622be9f' 
  AND token = 'Re7I4fTa03voia4GmhEBfvoH4hTn9xqBWUcXmWd/kWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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