SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '16466522b54b98638f037d646ffafefbf4fefd04c316a0af9411c9c402685a56' 
  AND token = '9HBc/1S/8u8FLzZZdyJi313nLVEJ7h5OV8IzknB5SUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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