SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7219f1a1237933a7b035c71445603e0c3a7df14641389453c48fb6466ae83a21' 
  AND token = 'pQVYDkgrGT9xbUiK1C8tFsEZmPCCsXHdvkpBPjuuuLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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