Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb11bb402595f3d9c3e8fa4d69afdc620a17f6b2544c24c1859eba3bd2e6c1b5' 
  AND token = 'FamMhDvXWjMmFdCSJTW9QwWCMT5WlEkfa4uJKtULGJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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