SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a41b5b6dad6c0a70332d649348a117642bb96cca8761ff7d1d97190fbc922456' 
  AND token = 'm1ttU/zyzWwJv+oB+xTleNqzHZzCbkhbDsEeqQpxHnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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