SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9de52d0dde7eb3fd705ab69983291f1e3433be1e8ec3da6b339e725c627cc6be' 
  AND token = 'AKC+m83w2ueg/M8xyaOqCYgxtQ1EadnEezIbSCYnhEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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