SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a563279ef42120a082c788fd9e169f0aadf736fe600deb24dff2a2002b895ea4' 
  AND token = 'Fgtzvq08+SeSOT7pfomQ+TjGK/gJwwo58sGF7YrWL4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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