SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abe189e0fc42bb092db1868f6faa48e97a58f391e7a02a0f46a0014db96a03a2' 
  AND token = 'wHwRGHZPu8K1CncxfuutxWgZpj3EcXQAFg0FVQHZ6GA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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