SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42ab744ec4317c62893b221c116ee207f573c1573f520f1022bd4e2a4ca6de4b' 
  AND token = 'wmY0pynuz4zHi9vzYnVqmhsJH7kVx86Ejl6ywOXWTXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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