SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '22c7704222fd70f1ea13cdbe28b76561559e18006e6342e4232dc5c2abecc72a' 
  AND token = '8PC2UaYgVtaL0cJ002Pq0PtK0pp+oGNyGfxyIu3SiMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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