SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '860648607cc75618e4d7b62913fd45f9a1b333b7536e23a759d691233a58412e' 
  AND token = 'Pmy8LjnCWz7YS6IPOBWkqTIVqpP6okX81FWfvSu7RUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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