SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a43c90f2a78b32ba3b527f9834534a5bc9fe855d89cf300b90a638c84969218e' 
  AND token = 'nRM/JFqRC4f/+YFIVxqufLSZZlQXaXNf7yRwAIo15Og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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