SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c3a6c96bbc5c497a80918874f646ca744c620c71f0f155a35420dd7461f63ad' 
  AND token = 'fj3tEhJHviJXMkAMqSeL31K35Y6+rr7xTNUDiMjmXaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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