SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fe03aa0e49e9da11f73fe0106f2460c93049db85a476a282e67718d3e9cf7f53' 
  AND token = '2UIn8fKdpHFN59VhSwdKcMFZ6NWQ6Bk7eVM9o6vA0Tg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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