SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0b408cd29b9fcb0fc736905c9ed95db8664d8ba1f303f47e8cdfeb7f54cdce8' 
  AND token = 'CNfbRAlToR733LIoXgWy/Is1MJBG0R4JLlQm4nQuul8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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