SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9e44458873d9c41d18af19cce4ab505435a7b9a7d5ba4c7bdb96d07c06621b21' 
  AND token = 'IYEWwBSrOQq9kmhwecEkJyLJN+PxzGQCt/po4MmPpzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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