SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5966499800489a1ca1c0bb503e07914f5596fc404b4260718c0e946963ecd6a' 
  AND token = 'y/yZyoTn9zNus6FVeLexKvOV4BqEDn8fGMLJIs3yI28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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