SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3af609a432848640d62d3a7c28bb25ff9c56f43c666d875b6f49de1e9d32d82b' 
  AND token = 'LUbhoT4+JVri2KMOSJYn5HqEZzdK6QgbZ/kMzidprls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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