SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a292ab54c49baf67a9806679e5c90b1eaf2623d9dc3b8ec68f24ae221c4f98f' 
  AND token = '2RKyu0ne5pw08DB1zV3XuPjqnKx5g3FMCtZcLlm+Jh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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