SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20dd473641f9950bd2c807979692a5b0d5b46eb432c25e9a79d114ee07934dda' 
  AND token = 'SM7jcN9kPumElX+gx6rZZdh336Voci9DfDQug132Hqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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