SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1b66866045bfea06d4c32c243bf7b4713a35ffc216d1e79c1a4192a5fdd3a6d9' 
  AND token = '9Fkt3nh2nynNKVnJBg/ojLe/yMqnSGQr1J4LbANgYYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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