SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a19b93bc607b24dd789865c072b8cad22792e2078f1225731f9d6de8552e08f5' 
  AND token = 'W44aWyVVrZVxsQMXTln8pJ/YwfQMquXMv1PkZCjO1VA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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