SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbe3d89917a425c7713ac7151297d29d4924554ac61fc5e40c67e0a043f45bb5' 
  AND token = 'IZwWoKMCLl1MErttolje9L0yHtjFS4gN3xWrYJYmhXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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