SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a580e55de8295dbc4f0b46cb509c4dec0219ca83d70175c1477294f3759a4232' 
  AND token = 'ckYAX0AmmZHvJB5/BPixjD2qozlhcz6CZDrdhgl7+lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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