SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc2a3921426a33e2bf6ae580b6fe2c98ee65f7b44b607f70dad4297f57d8f228' 
  AND token = 'n2ivjprq/+5WuA/l/+9jfYnEwCsgHtzJH3Yk5Flk8e0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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