SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a6fff99620ea3c148f7e0b8ac308e238d362ddb7c7e5cdf82a0a8c433666985f' 
  AND token = '+W0uBqOSqxDZGwfydojbQl7+KuiZbY327qZQTV+1O8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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