SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98559e1bd066984c322d8d4e9532ecfeedb55b396bde30bffcee12dbb1b94ca5' 
  AND token = 'Fg0ItBQARMMLR5LZ9MvHB76srC0W+XgytmWm8RnKHpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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