SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '50ba0ac727ffba71f7f4d362e46384c6d151be65d1930ce3d0853bd0440b4534' 
  AND token = 'TTgBtt/mc/FvStIFDNCciqgW1kxZLcOBkFFJvUP1KCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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