SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5157af8e9628a6abb971f4b807853379d55c3e3837d644942458cc4a06649e54' 
  AND token = 'im9n8Xa9e+C9vnOqQt7JZh77/hDO/uzmj5gRVJYVE6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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