SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efc47cbbe5683fdc7e0a1f78192b3f233422b667e9b6009e460abea5522c393f' 
  AND token = 'PnVuOlvdA+zyUVbI9sDMs0lO0ar/v14kvRB4XwllGH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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