SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36a13f0a9e4ad8f0b13e7a4651922850c96cc95afec08c958b2d64d7f4f54d1d' 
  AND token = 'p4/HAtBz6kPJhg2LSnsWJIwLfGCro4uMJNB/xVo9Ymc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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