SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '063f999e48470e875c4b847abfcaf22487e83b63ecfd4f43ce4ceff49bc25280' 
  AND token = 'cAEaOu0F4uR1W2CEoG/ygLFtATx7nAVQ9ESZMWsXJug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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