SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c0a889ea18be4841fe6daebcf7ce0edf7fb2014e0dc0a7fb650713fc99e805f' 
  AND token = 'lfihi/qVsdXOrtt55luCIqvZ2WmyZTVwvP91G0Ws148=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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