SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '256025e744d9b1e33c1d5f04e6728a0a17057c89da649888a35afde64d01eda6' 
  AND token = 'gll4aVwX+HxKIDthyLmVfwypIeELg3brhcMt4klJvyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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