SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca44653f5edd9d1c8e57b0ae6891b687ba60cec736e3ad2ce25ae49d1587da4a' 
  AND token = 'ZGJxi2OgZxyk7AfwLGFVu1IJL95P4Ua5P9OnSg9KFxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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