SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9659e65272fa47c1d642a62f98de943f389c105ae72b509f09d2b8a4614ad410' 
  AND token = 'owWHCbmo8LhjMvpzfgWTJiK3jlVXWvQhgOBX12rS268=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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