SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ab862d4bb3c7be8f9bcde19b35efc3ee88be2331bbb9c7cf0faf0759a0d82a8' 
  AND token = 'KYVwkMYFf/11GdxBzir5Kd5JqY0EAGQ41tsBVusS7vc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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