SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4698affc81a35782d7eb28b377b972ef225929709edbf5e90567c4463349948' 
  AND token = 'YAwTH+ftmQVa5Trst6/99Y8usDLTXrhtKzXx+BnQxFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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