SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb84698f35198e895c06f0974b5cdc3c63a5d714c6f9e1ac688a3211a58909af' 
  AND token = 'h4bTouRsGUYsUqMx5RFWZ+ELjlcBZRpRfHoRayrHJf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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