SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8da7d21ad694c0408ca1521580bf7e1e79eaab0bc05f53fbeb708e588ec29ea8' 
  AND token = '+womrqoqNaw9tBoALj8kweEzxUd2EOW/vG5oeHFpuuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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