SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd137a54986312eb1f6d20127fdc34d79f6c6cc490895df91fc0ed8d98eee101' 
  AND token = 'GIiSSzvq+X07j2WzeNRUAQWPtAiHwQVknYtuKD9wBF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}