SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0baa3b07ae510dc5711fb7da0a8c2d694bb3e58f3ce73895fbe19ce30bf2e8ad' 
  AND token = 'sTxX4YB0DskhNCdZQEQXtzu6kNWgDWl0XBmvYPrMWPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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