SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c970243505b748719f842d6ef1f4ea1683ca1e684476d8fb10fb4ca732dabab5' 
  AND token = 'JoDr8W7UOz6wfLddu3lQjyhPrs6EmOlRLxNyMDLHRzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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