SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed50af0963753f6178f3408a89e504a26df52154f8acbbc14fb6f926a9416016' 
  AND token = 'zfZp+lyjhnb6++tpdap7yDCiaPXwRTT+wvivmdWKOug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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