SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baeba6d88e7c8decfd452d471748aaf5de36c914eb48f2669bbb12d57648bd96' 
  AND token = 'YxWSNNq8Dt+vJa/EePVtfpumSJ0obgxDgIw8oXz8ymI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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