SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '899653b6cb429fb323ffd5ebc3d889337d6098b21276369897a67ff6fc0f0ea0' 
  AND token = 'nAoEl8uWf5t+UW7uV9oBs3mGISUQ1AiAgn52x/b0k/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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