SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12c69cacd293727fb9453a24a612917e577b0601619c1c76dd47d2caccdfe31e' 
  AND token = 'TybRr6vtJeAfS44gTcByqXya7k1xC9k7IyI7r+NRXCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}