SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = 'fcbff98af5fd6bb053898fd4a3592c17dc60ce8ed68485a17a56f71b107af3e4' 
  AND token = '3UbvwDUnBCJ/XgzL7cNjv+Rw+DY+YUZh1RD6L3Sxj8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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