SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a01c446947d4cef8813efb5bff20d8b354d8b192ca79f1a3bea7c8191ed356a2' 
  AND token = '7ZTT4HzcWcy0tlI+qxhgbJRQayHlgYjMFDzlsq8ULTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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