SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a88e2530613089972807a3946e2e6ca5a3fea455d75797789d7cf22fbde20f4' 
  AND token = 'r2gxok0JvNNw/hWGmbhQxWwb8FPgo9PsdtMcWRbaUvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}