SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '328b36790d20ff03f3895063840aa34237765d281b27fb43b1a3c086395bfdc6' 
  AND token = '8bQJ+z3gC5EhKOHmA1T+U6nZRICzGA9fzd6OlkUCwKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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