SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eadde02a5db4aac35562deaf7b0584314a8c685710944877a4fd41ea8a1349d9' 
  AND token = 'ZDfO06iNewAgA6H2UwLAamNn0CkHCgQKhU+hjoj6lrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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