SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db6ee0a89e5c6c5bb131535836d04b93c99a2d22782ed60e92e72efa3eaec1e3' 
  AND token = 'jOFpv6NAEE1dLjgVmnOTVn7xicHJfGA/h40HKSkVs0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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