SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e11d5b4d0ebd07da20a66922f44ccd797ff60c43913e1b7f5f615b67d51a63b8' 
  AND token = '/tMFZiIlfCGsev2qdZs4zu2wDXLJFzQGWQXj8k9cs3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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