SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fc7754d8aab6bade108ab1c6dca05553972be36238d349978e80bf7bbbd80da2' 
  AND token = 'AXxWnQFkBH9JGoRHQzKOlhdAqiFkLcPh230/3i5794s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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