SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa11483c48c87179101a9ed6e57fcd833369fe9a241847ddc6d55b647fdcffdc' 
  AND token = 'b/FD1Ik+vchEjz5LUFScn/9RyPBYrJpFSXb6uOdJzvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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