SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e4c098dffa7acea6985ceb8c7267b377dfadc90ef747b5a08d58279ce24eb43' 
  AND token = 'zn8A18A5WDLqnbXfn4co6zaUdGa9KQ/MZsQdX8DYkXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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