SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae19b8bb9008cb548bf8ffe16fd59d4d0a23a9ca34d5c8447dd80be46c4ec53f' 
  AND token = 'XV/J7VvSkJktBDtwJqyC0OjcDVr3jysO0KmUYc4YuX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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