SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f1b56c704fc86611fc59a1aedb091ed7e45d5cd721428bea7610a3595b5369c' 
  AND token = 'ouPFoDsZ8xqtPj/BBgmFCVoZFnzX97U4fA9loV9nC1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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