SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5cfb12ae4f651324a5433c225d383e2c54eb57beccddd2f8e75544c688e2697b' 
  AND token = 'PAEzaaUyFwHSeklno/6Bs9sj+m4r3UHOSGoqhzekUdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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