SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '723fc683350069f9c72f998fdd85606483b6d64e5c577a7f2371676db9799da4' 
  AND token = '4OIYBqhCqwimtLTVWh/ZDWtoTwHUNutcclJccYYdvKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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