SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b56643af1156e27d83c5568ab6311b53af1628e9e3e8b3bb8982f67903d9a9f' 
  AND token = 'UI+RtmsYpI2aONIELsxaHbOvnSg1r7KXXrFlxgB4DWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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