SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f67517e91c2e7890261892ca884a1364cb05bf00e02203b8e247795c6a7fe59d' 
  AND token = 'W/cGUIvQAvfdmbK0cad9gGWBHJ5kro/llZ8gR7RxhzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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