SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '594c19aac9dfdbcb0f17d57a2f9605a371784b55ad871a8bdeaaf5b56e2e9df5' 
  AND token = 'pfv/ZN/keBTv254rVI1Q91f2XrrTTeNzCm98TSQJ0/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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