SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29931560c17a89f38652bb2eeb1ad7536fe74dea5caa98141c10f8ce86406c67' 
  AND token = '4uLS7ocmU+L+dBkQGIQKxKH4w5kqgMizCKfN/YDzcJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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