SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '432e5a92062777a2a586a42d01cb02c91592c8bcf927f6126a422666e1ddc60b' 
  AND token = '/9jTdReO06ZdAbY8pfsRtz5l+xzpCxLmhWKSnkIe19c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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