SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf2d61f7649466ba68f57f58edb737238db06b56cf0a47b94953055b6e3f9d3b' 
  AND token = '2vdIqxXU1ZPV3R+Lx/O5Gp7t01RlHvPYDs/Mp3B3BeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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