SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa0fd68584ee07525c0035a69bd6de4756413e7aaf102507da5c78dea9dc9a31' 
  AND token = '3QGrIqKJPEPvnMBVT/k87JUcyVi6VeafNUUvOkYXK7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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