SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c2817f1e753c2737c83b8bb04720d8ff12a8cc1cc116e4b3a090639418355b8' 
  AND token = 'AJkqCpZBSdBziy9nVpqDuH6LDD0WJnYxcglyc5IVZ0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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