SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '017c95ab1c28b51b1b91dfddbd848101eda22176eaa7b8ebd12b24ee597fc53e' 
  AND token = '3zevcq+2g8CXN9L0XD8jjjTjboqqYAEdzQTgFddhNCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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