SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '769535f9fedcd5eaa0a3061f282cf33bbf09a23c6032b095c572fffe01a536f5' 
  AND token = '9BcYw2+mBLbA9GUvrzSfazghlZk0+C3ApQ/XlS0ssJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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