SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6253b8c76ba143ca14ec7cf7feb69b1d2dbbb46b1a608d0ee4caeaf583e643c7' 
  AND token = 'mNoHc58svamPRUKOprXH3fxqUEUED1q0/eAXrZbkUTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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