SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13f14d663c0d4efe214bd2f08fdb746a7749a5fcb98a7ccd39a87c888ccf8851' 
  AND token = 'vkMkcgGkxIZ5sClSRYU74bOxX66KIX8uerBD27nI4B8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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