SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8ac2af812e36c1475d58cd13c78f59001d2aa9d232db326b2912df6eb8863b3d' 
  AND token = 'rr+7bqnpHm92m4+AiUCL7oB2wXQCgkcJF4JgbRsv7Q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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