SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfd17f1cf0e4efa60bb428c7640625e40cdbdf62ef7ba92227ae3f569879418a' 
  AND token = '9X8l+zw50Ro5BmRnyyOtEQYUkWPjDZEO8PoXyOZKV9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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