SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3985ca11999d15aba762f874ef8edd994f08c9c8997c9baf49c84c1aba5957a7' 
  AND token = 'fWgv+6O5d919aa1yfl2YFfCjE8SVuM5itCa9vgm/MGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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