SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5239327dcc2aae687115640706c5be9a5a11bc883c056992bf81d14b65dfd2a' 
  AND token = 'LX3Z/5pYc9NtDi8qlALNhummOL0iIx7xEhydB8CYzlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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