SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'af819d9608967c341ac750a90883489705811e64ebdb81f31200349db5af9933' 
  AND token = 'P6V/0HK99sxo5ZdMiY4IA5r7OZLohtmqD+S2TYrhX/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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