SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ebb8d9d77e951e738729148f7f7f64beb6867ea74e07f95d399efc1ea4341df' 
  AND token = 'ojptvdwbREF3bWkNsB8nQ9cOPCcFu3K7D76uCMOagvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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