SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06be082b3d195b7d903cdc18833977ad8720efeb1d9211142b58dcecf858b40a' 
  AND token = 'FOcSWug+hDVYfHq8WBcUlwILzOAlu/N7gC1dTZvm1C8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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