SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a0ee862c6d9102fb30d0a48d809f69565d0a65c408e6c58a22cb5efdf8acee9' 
  AND token = '88CSohi5YtYKMxnbrDspVIXxZO68MCN4VH/ChWkZqXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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