SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4b7ad4a955aae83476316ff7b0fe78be2bae7129088ba4623cbd69c76f001d6' 
  AND token = '0+To+RAuRyrfDcnToqvTmfUnQyZh9Anqp1I8PQuwOIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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