SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e06770da8ec8be3e08b2fefa7c826b84ad5186f2642ad8c068ba5d614372cc11' 
  AND token = '7CaKvDTDtafxKH7A7oKBiqGFgpPIzXn0+QFkEUtaGfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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