SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8a3adef82da4e59b85f65f7fd042b2d5a4627c518bd6ee422ead6d03f99d8f6' 
  AND token = 'cddrOs4yfuSWyuo5WfI/4LZDzCH7hIGymTah6Jh1eYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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