SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cde24686e6c54dfa6de869fc77ac2bd60a9a3cb580fa5526a162c10694fdd34' 
  AND token = 'hg+YWtXDMOqPFSH19nW5nH8Zz1UnevMEKDiOQQAdGLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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