SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cea5d5ecebb1618aee399f49662be37f99a592dc0ca78f81b50eaca86bff460a' 
  AND token = 'EKihdBC2TvP7NTSjVPwU7Wf/lhtLfjrMlgdSyX60v9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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