SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ef69caf8cabebc4f312bd093bd8a5dd619eabbbe050f831b122ecf6c025fc87' 
  AND token = '8pYm3iaBJKVTlVQcT3kQIR98SXfnL4ehndOB4oDRGVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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