SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '703433b7aa4a262f92c650f0ff46d3832f8dafb1d38c115edbc6c7e5ef90d302' 
  AND token = 'sAMxubSJlpnRsMrxEIImJXAZ/gKJTwglsCcLSQPFrww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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