SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7db962e7833ef21cf991208a0dc696dc110d1e9fbf0e0d4390db8e716fc21b1' 
  AND token = 'JQ1hPSWzKPDycJEVhW3s3aOCBdLMJLhMauFlOokN4MQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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