SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8388c60a3338f83c6030d6d397616b83c565b6b4ed653a937b09f64fac53c209' 
  AND token = 'rAJStLKbNJEUGO1oUI/6wNj5y/wQRL3+otuGCf/Cf+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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