SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc5e1ea26b7d7eddc5ba1ad3cd446d4b899bca5f54384681027a0a2d94ffac00' 
  AND token = 'YS7AzFvJGQ66jskExv8O5GHisSABtYSZ0fgKnwABjG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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