SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '999789d9b0590c21eb18b98628b5c1ef2d119158b4b86f57870fced33fb45ba5' 
  AND token = 'pgYsfuGB3laoT2CQsdgjrLa6gZz0Oz0X5wPO/LsaUnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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