SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1a43bbd2ec6d45fdef185a8fb65249eb9d3c442a7d8b6a2da7f6a46031a66e5' 
  AND token = '75jUeWwawoB/sTxzclwBvOHCZ9LxZm7pAjIqyUpuiVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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