SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71cd7a3176068295cf56a9cdf1d658e1458ad08e0896ed393bf9745bada90023' 
  AND token = 'NCD2LoZzpERRPjfmduxBZKc/ecZe8jzWzlLFCRKY+pk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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